Duncan is a crafty juvenile delinquent who comes from a long line of policemen and policewomen: his dad, mom, uncle, aunt, grandma and cousins are all cops. He knows many tactics from his time spent in juvenile detention centers. He can carve a picture of a skull into a tree trunk and lift great amounts of weight (such as Owen, who is more than three times his size). He has a brooding, obnoxious, sarcastic and flirtatious personality, flirting with Heather despite his apparent dislike of her and mocking Courtney whenever she gets near him. He also gives Courtney the pet name "Princess" to tease her. Duncan loves to break rules to better suit himself, but sometimes the consequences are worse than what he intended. Duncan also loves to make fun of the other contestants and pull several pranks on them, with Harold being his main victim (later intensifying it due to a certain move Harold made in Total Drama Island). He considers himself as being "straight with people", rarely pretending to be what he isn't. As a result, he has been shown to either get along with or make fierce enemies with his fellow competitors, although it is more than often the latter.
Despite his mean attitude and demeanor, Duncan is actually a good person at heart, although he will never admit it to anyone else. Such moments displaying this side of him include finding a new bunny for his friend DJ after Geoff loses the first one, carving his and Courtney's initials on wood, and defending Lindsay after she is betrayed by Heather. Some quality time with Harold also makes him consider ending his feud with him after so long, though this does not come to fruition. As a way to express his feelings for a girl he likes, Duncan uses his knife to either carve her name or her face or protect her during challenges. In Total Drama All-Stars, being on the Heroic Hamsters starts to bring out his nicer side (which infuriates him, as it ruins his "bad boy" image) but soon "proves" he is a bad boy again by blowing up Chris's mansion.
Duncan apparently joins Total Drama in order to avoid returning to juvie. He is the seventh person to arrive to the island in Not So Happy Campers - Part 1, where he is quick to make enemies with Heather, Noah and Harold. He is surprised to see that Camp Wawanakwa is not a five star resort like it said on the application. He told Chris that he doesn't like surprises, and Chris replied by telling him that Duncan's parole officer can always take him back to juvie. He is placed on the Killer Bass, where his mean, aggressive behavior makes many afraid of him. He finds pleasure in picking on Harold and making his life miserable, pranking him on several instances in Total Drama Island and Total Drama Action. His reputation is also well known to the Screaming Gophers and as a result most campers keep their distance from him. Despite this, he does manage to become good friends with DJ and Geoff who he often hangs out with. Though Duncan himself is a strong competitor, he is not above cheating to give himself an edge, though he is always caught in the act by Chris, who frequently brings up his parole officer to keep Duncan in check.
Since the first challenge, Duncan is skeptical of Courtney's so-called leadership skills. Duncan is in fact one of the first to suggest voting off Courtney due to her poor performance in the challenges such as failing to dive off the cliff. Likewise, Courtney dislikes Duncan, often mocking him for his punkish appearance and his reputation as a criminal. Despite this initial tension, the two of them show that they have feelings for each other. Though unlike Courtney, Duncan does not deny this and often flirts with Courtney, calling her pet names. As the season progresses, Courtney continues to reject him and even kicks him in the groin at one point. In If You Can't Take The Heat..., Duncan, along with DJ and Geoff, prank Harold after he continues to leave his dirty clothes in the cabin, in the end leading Harold to promise never to leave his clothes on the floor again. In Who Can You Trust?, Courtney discover that Duncan found a new bunny for DJ, after Geoff loses the first one. When she asks him about it, Duncan pretends he doesn't know what she is referring to, before finally confessing. Realizing he is nicer than her lets on, Courtney begins to see Duncan in a new light and promises to keep it a secret, much to Duncan's annoyance.
In Basic Straining, Duncan spends most of his time pranking Harold or provoking Chef Hatchet instead on focusing on the challenge at hand. Courtney tries to make sure he doesn't get into trouble, though Duncan teases her that she is doing it because she likes him, much to her frustration. Eventually, Chef loses his patience with Duncan and sends him to the Boathouse. Courtney pays him a visit and after a brief conversation regarding each others behavior, Duncan convinces Courtney to break some rules and join him in stealing food from Chef. They return to the cabins and share the stolen food with the other campers. After another conversation with Duncan, Courtney pulls Duncan and kisses him, beginning their relationship. After their team loses, Duncan is shocked to find out that Courtney is the one eliminated. Unbeknownst to Duncan, Harold had tampered with the votes to eliminate Courtney, to get back at him for bullying him. As the Boat of Losers sail off, Duncan has a tearful farewell with Courtney and gives her a goodbye present, a wooden skull that he carved. He is happy when Courtney said it is weird, but that she will cherish it.
Soon, the contestants are separated into boys and girls. Duncan and his group immediately gets along with the remaining boys from the Gophers, Trent and Owen. Despite their bond, the boys immediately distant themselves in No Pain, No Game after Chris announce the merge. However, after Trent is eliminated in Search and Do Not Destroy, Duncan realizes that the girls outnumbered the boys and rallies the remaining boys in Hide and Be Sneaky to form the first guys' alliance. Although it took some intimidating in order to convince Owen, the other boys ultimately agrees with him to vote off one of the girls. After the challenge has ended, Duncan convince them to vote off Bridgette, seeing her athletic skills a threat to which everyone (except Geoff) agrees. That night, although Bridgette was voted off, Geoff admits that he did not vote for her, earning him Duncan's anger. In That's Off the Chain!, Duncan continue to lead the Guys' alliance and is noticeably angry that Owen and DJ are talking to Lindsay. Though another girl is eliminated, Duncan defends Lindsay when she is betrayed by Heather, saying what Heather did to her was "cold" compare to anything he did.
In Hook, Line, and Screamer, Duncan bonds with Gwen as they discover a shared interest in horror movies, even having the same favorite movie. When it is reported to that an escaped killer is on the loose, Duncan is the only person to take Gwen's advice seriously while others go off on their own and end up getting captured. Eventually, Duncan hears someone calling his name and leaves the campsite to find the killer standing at the Dock of Shame. Duncan quickly disarms the killer, only to find out that it was really Chef wearing a mask and that the real killer is in the lodge with Gwen. Duncan high-fives Gwen when she defeats the real killer. In Wawanakwa Gone Wild!, Duncan opted to form an alliance with Heather and agrees to help her into catching her animal. This alliance was only short-lived however as after the two of them eliminates Izzy, their partnership is not mentioned again.
In Trial by Tri-Armed Triathlon, Duncan is partnered with Leshawna, who he doesn't get along with. The two of them often argue throughout the episode, often physically, on who gets to do the required task. In the first challenge, they compete in an arm-wrestling match to see who should be the feeder in which Duncan wins by cheating. Later, they argue on who should sit at the front of the canoe and who should carry the other. Eventually, the argument begin to subside when Leshawna states that Duncan is actually a nice person and will not come up to his threat. Duncan pretends he had no idea what she is talking about until Leshawna brings up the incident about DJ's bunny, revealing that Courtney had told her about it. Duncan confess that when he was younger, his pet dog ran away and he doesn't want DJ to feel the same way. The two make peace with each other and continue with the challenge. At the end of the episode, Duncan choose to vote for Geoff for failing to vote for Bridgette a few episodes ago.
In Camp Castaways, Duncan is caught in the fight between Heather and Gwen. When the campers are drifted to a deserted island, Duncan initially states that he is happy to be alone with two beautiful girls but dismisses it as their arguments are getting on his nerves. After a hunting trip, Duncan attempts to leave the island with Gwen but they ended on the opposite site of the island and eventually back at the tree house where Heather at, with the recently arrived Owen joining them. After a heart-to-heart talk with each other at Owen's suggestion, the final four return to camp after seeing smoke from Chris and Chef's campsite. Duncan is paired up with Owen in Are We There Yeti?. Though Duncan often berates Owen, the two of them easily get along and is able to outsmart the girls several times. Ultimately, because of Owen's appetite, the two of them loss the challenge and Duncan is eliminated although he isn't disappointed. While Heather mocks him for not allying with her and Owen accidentally burps at his face while trying to bid him goodbye, he share a fist bump with Gwen, who sees him as a respected player.
Duncan returns in the finale, being one of Owen's original supporters before announcing of the party he is going to held if he wins. At one point, he and Courtney ended up arguing regarding the finalist situation but the two of them ended up making out.
In the special, he and Courtney teamed up in order to find the case with the million. After Duncan manages to wrestle an alligator that ate the case, he trips on a rock and sprains his ankle. Despite his pleas for help, Courtney abandons him, taking the case with her. When Noah comes by and mocks him, Duncan rips off Noah's pants in retaliation. After he could walk again, Duncan manage to make it back to camp, but is attacked by a moose. However, he wards it off with the moose head from the main lodge. From above, Courtney cheers for him but Duncan is still bitter about her betrayal and threatens her by saying he's coming for her next. Duncan ended up riding the moose on its back and is eventually thrown into the lake with thirteen other contestants. As the case was eaten by a shark, Duncan is among those who qualifies for Total Drama Action despite Duncan's protest of participating another season.
Duncan returns for the new season, continue his role as the series' anti-hero. From the beginning, he and Gwen had become close friends due to the both of them having many interests. This made Gwen's boyfriend, Trent, jealous seeing how those two have so much in common while he couldn't even start a topic with her. His anger is further escalate especially when Gwen chose Duncan as the first member of her team. Unaware of his anger, Duncan begin to pull pranks on Trent, angering him even more. Trent's jealousy had made him become obsessed with the number nine and Duncan only made it worse after telling Gwen the possible connection between the number and their relationship. This leads to a series of events in which leads to both the break up of Trent and Gwen and their subsequent eliminations. Duncan is one of the few people (the other being DJ) who still defends Gwen after she is caught throwing the challenge for the other team. He even tries to take her place in the Lame-o-sine but admits that he was only kidding. Before she leaves the show, Gwen wishes Duncan good luck.
With Gwen's departure, Duncan unofficially replaces her as captain of the Screaming Gaffers. He had win many challenges for his team, earning him the respect from his teammates. However, his hatred for Harold hasn't changed. It is revealed that Duncan had found out about Harold's action last season that caused Courtney to be eliminated, leading to Duncan intensifying his mistreatment to him. In addition to this, Duncan also occasionally mock Harold's feelings for Leshawna. Meanwhile, Leshawna tries to pull Duncan and Harold into forming an alliance with her in order to protect themselves from Heather. She first tried in One Flu Over the Cuckoos, but at the mention of working together with Harold, Duncan simply laugh at her and reject her offer. After winning the challenge, Leshawna started crying, stating that she is worried about her friends' safety throughout the episode. Upon seeing this, Duncan nominates to give the reward to Leshawna and everyone else agrees with him. Two episodes later however, the Gaffers discovers that Leshawna pretended to cry in order to claim the reward all for herself, angering Duncan.With the discovery of her scam, Duncan gives Leshawna the cold shoulder in Full Metal Drama and tells Harold and Heather to do the same. For the military challenge, Duncan once again takes charge of his team and questions Harold's usefulness. He reveals in the confessional that he always dream of joining the military. Duncan easily wins the second challenge, creating a giant skull with the explosives and successfully defends his team when the opposing team launches an attack. With the situation becoming more tense, Duncan admits to Harold he actually has a small degree of respect for him in order for them to retreat. Their combined efforts allow them to defeat the Grips again, winning immunity for their team and taking a peak inside the Chest of Mind Blowing Secrets, which contains nothing inside, much to their dismay.
Duncan and the rest of the team continue to ignore Leshawna in Ocean's Eight - Or Nine and doesn't even bother that she is missing. As his team attempts to open the vault, Duncan is annoyed seeing how incompetent Harold and Heather are and is even more annoyed that they forgotten he is an experience criminal. After seeing that the other team are having the lead, Duncan tell them to abandon Leshawna and improvise the tools they need for the challenge using Harold's belongings. When their team are about to "rob" the bank, the teller reveals herself to be Courtney. The sight of her caused Duncan to faint. It turns out that Courtney will be returning to the competition and is placed on the Killer Grips. In the second part of the challenge, Duncan easily reassemble his team's go-kart and drive them to victory, reaching the finish line before the other team despite their kart run out of gas at the last minute.
With Courtney's return, Duncan know that his team must work harder in order to win. Although Duncan still harbor feelings for her, he hated the fact that Courtney would stood so low into using dirty tactics to make sure she wins the season. Courtney on the other hand is angry at Duncan for being close to Gwen, believing that he is cheating on her. They are pair up against each other in One Million Bucks, B.C. and Million Dollar Babies and Courtney wins in both times as Duncan tries his best not to have his relationship with Courtney ended up like Trent and Gwen. Meanwhile, it is discover that Leshawna had badmouthing the contestants during her trip to the spa, calling Duncan a softy whenever Courtney is around him, further angering Duncan. However, upon listening to her apology song, Duncan and Harold allows her to stay a little longer and voted for Heather instead.
Upon reaching the merge, Duncan and Harold finally agrees with Leshawna into forming an alliance. However, they went behind her back in the next episode by forming a new Guys' alliance with Justin. They agree to vote off Leshawna that night since their biggest threat has invincibility. Harold initially refuse but after some convincing from Courtney (whom is convinced by Duncan), he agrees. Meanwhile, Courtney's enemies (including Leshawna) are also targeting him, believing that eliminating Duncan would made Courtney lose her edge. In the end however, Duncan receives the last Gilded Chris and Leshawna is eliminated. The Guys' alliance continue in The Princess Pride but tension rises between Duncan and Justin throughout the episode. During the first challenge, Duncan pranks Justin by tricking him into walking the wrong direction while Justin is blindfolded. Later, Justin spotted Duncan is cheating but Chris ignores him. Later, Justin become attracted to Courtney, leading him to a fight with a jealous Duncan for Courtney's affection. Their conflict, along with Justin's elimination later that episode, marks the end of the guys' alliance.
In Get a Clue, Duncan manages to steal one Harold's DNA when the latter attempts to steal his using a complicated trap. Throughout the episode, Duncan is easily tricked by Courtney several times. The first time is when she treat him dinner and a massage which is actually for her to steal a strand of hair from him (even though she already took one from Lindsay. Later, she manage to sweet talk him into going to the roof of the train to check whether or not it is real and is severely injured when the train pass through a tunnel. Because of his absence when Chris's body disappears, Duncan become the primary suspect and everyone (except Courtney) handcuff him. In the end, Lindsay wins the challenge and found evidence that Duncan is innocence. To make up for her mistake, she invited him to the movies. Because of their differences, the two of them find their date awkward but had fun making Courtney jealous. In Rock n' Rule, Duncan wins the first challenge by playing his guitar casually and then smashes it in true fashion of rock and roll bands. He also perform well in the second challenge though he lose points for the damages he caused. In the end, Courtney wins invincibility and Duncan is targeted by the other contestants again. However by pure luck, Duncan is spared as Lindsay accidentally casts the deciding vote for herself and is eliminated.
In Crouching Courtney, Hidden Owen, Duncan trains Harold in preparation for the first challenge. Through his training, Duncan is able to bring out Harold's inner strength and together, they win the first challenge and move on to the next. During this period, two of them begin to make amends as neither of them want to sabotage the other and even agree in sharing the reward together. Just as things between the two are becoming better, Owen, under orders from Chris, convinces Harold to punch Duncan which he does so after Duncan makes fun of Leshawna, ending their short-lived friendship. This action gives Harold enough confidence to give Duncan a taste of his own medicine by putting rocks on his bed in 2008: A Space Owen. After Harold accidentally killed Duncan's beloved pet tarantula, Scruffy, Duncan votes him off. Before he leaves, Harold pantses Duncan, to which Duncan admits that he "kinda had that coming".
In Top Dog, Duncan and Courtney spend the night together before discussing about their relationship and Courtney decides to give him a chance, provided that he read and memorize a thirty-two page long letter that highlights all the mistakes Duncan needs to correct. This cause Duncan to be sleepy for most of the challenge. In the forest, Duncan's chameleon disappears and he ended up falling into a pit. Duncan slowly begin to lose his mind and to quench his hunger, he eats the letter Courtney give him. Two days later, Duncan returns to the film lot, dressed up as a wild man and armed with primitive weapons. In wasn't until Courtney kissed him that he return to his normal self. Owen then tells him that his chameleon was with him the entire time, blending with the color of Duncan's mohawk. Tired of Courtney's overbearing rules and control over him, Duncan voted her off that night. Angered by his betrayal, Courtney break up with him. Moments later, Owen is fired by Chris, leaving Duncan and Beth the only contestants remaining in the season.
During the finale, Duncan declines Beth's idea of working together for the challenge as he wanted to claim victory for his own. He manages to get a head start during the first challenge but since he is unable to answer any of the questions Chef asked correctly, he is required to compete all the season's challenges again. Beth eventually catches up with him at the final question since she knew much about her fellow contestants. To Duncan's delight, the final question is about Courtney, whom he supposedly know a lot about. Unfortunately, the question is something he didn't know; "What color is Courtney thinking of?". As both finalist are unable to answer the final question correctly, they had to compete the earthquake stimulator challenge again. Duncan and Beth ended up helping each other to make it to the finish line, resulting in a tie. In order to determine the winner, Harold suggests that the two of them compete in a contortionist challenge, but this too ended up in a tie. Once Chris returns, he had the eliminated contestants to vote for the winner, after asking them questions. No matter which ending occurs, Duncan ends up back with Courtney.
It is revealed in Celebrity Manhunt's Total Drama Action Reunion Special that despite the couple's popularity, Duncan and Courtney broke up again and Duncan had filed a lawsuit against Courtney over custody of their pet raccoon, Brittany (a parody of broken up couple fighting over custody of their child). Meanwhile, rumors begin spreading that Gwen is beginning to have a crush on Duncan, putting the situation in a tense position. Duncan joins his fellow contestants to New York to stop the Dirtbags but en route, he and Courtney ended up making out, sending their bus off a cliff. He remains at the bus with several others while Geoff finds help. Eventually, he and those who remained are saved by Chris who announce that they qualified for season three, Total Drama World Tour.
Duncan starts the third season in a very good place with his recently reunited girlfriend Courtney, and his close friend Gwen. Like Gwen, Duncan strongly opposes the idea that the contestants are required to sing every episode. In Egypt, Duncan and the two girls would work together during the first challenge, but things get tense between the girls, which annoys him immensely. Once his team makes it to the top of the pyramid, the two girls continue to argue and Chris shouts at them to get down, as it's time for another musical number. Duncan finally snaps and runs down the pyramid, dragging Courtney and Gwen along with him and yells at Chris that he quits, shocking both Gwen and Courtney. Duncan would officially leaves via the Drop of Shame in the next episode after Ezekiel had taken it. The exclusive clip shows that after having trouble activating his parachute, Duncan is dangling from a tree and is surrounded by scarabs.
From his departure, and for the rest of the first half of the season, Duncan would be mysteriously spotted all around the world, in places like Scotland, Sweden, Texas, and Italy. His disappearance and sightings had been included into an Aftermath segment called "Total Drama Fugitives". It was also mentioned by Blaineley that Chris had been searching for him, even sending giant Drama Machines everywhere. His absence was also brought up by Gwen and Courtney in Newf Kids on the Rock, both accidentally reveals how much they miss him in the confessional (though the former mistaken him being her boyfriend last season instead of Trent). While Team Amazon are on their way to Newfoundland, the two girls believe they saw him standing on top of a mountain but in turns out to be a rock formation that resembles him.
Eventually Duncan ended up in London for a performance with his band, which coincident with the latest country the contestants are visiting. He was captured by the two girls he is closest too when they bump heads in a club at Whitechapel and is brought back to the plane. Upon discovering where he is, Duncan quickly looks for an exit, but Chris stops him, revealing that the whole challenge was a plan to drag Duncan back and force him to fulfill his contract (much to his chagrin). He is soon placed on Team Chris Is Really Really Really Really Hot. He is soon scolded by Courtney for abandoning her before the two embraced but at this point, he is completely over Courtney, and has grown romantic feelings for Gwen. While Gwen is using the confessional, Duncan accidentally barged in and after a brief banter, the two ended up kissing, with Tyler as their sole witness.
In Greece's Pieces, Duncan threatens Tyler to not reveal about the kiss he had with Gwen. Unfortunately, Tyler was pressured by Alejandro to reveal his secret during the tie-breaker challenge. Upon finding out that he lost another chance to be with Gwen again, Cody angrily punches Duncan, starting a conflict between the two. With a target on his back, Duncan was supposed to be eliminated that night but Chris wanted to prolong the drama and eliminates an intern instead. After a messy break up with Courtney, he and Gwen would officially starts a relationship after they shared their second kiss in The EX-Files. Unfortunately, their time together was short as Gwen is eliminated in the next episode as a result of Cody and Duncan fighting. Duncan however would not forget about her, and is seen carving a picture of her face on the side on one of the first class lounge chairs in Sweden Sour. Miraculously, despite all the wrong actions that he had done, he manages to get away with most of his actions until he gets involved with Alejandro, which soon leads to his downfall.
It is around this time where he started getting involved with Alejandro, with both getting involved with two women on the season. They both come up with a plan to mess with Team Amazon, by pretending to fight over Courtney, and for Alejandro to flirt with Courtney, so Heather would be jealous, and the team would completely self destruct. Duncan, however, admits that he does not trust Alejandro in Sweden Sour and advice Owen to do the same, using Noah's absence. Once the teams are merged, he thinks that Gwen is going to return (missing her dearly), only to be told that someone else will be returning. Duncan is forced to work with Courtney for the challenge, and despite their bickering, they manage to win immunity for themselves. In order to get rid of Courtney and secure Alejandro's vote, Duncan agrees to team up with him though he still has his suspicions over him. Regardless of Alejandro going against his deal, Duncan is finally be able to eliminate Courtney in Chinese Fake-Out and was not even afraid of her threats. In the next episode, Duncan and Alejandro teams up again but he is soon stabbed in the back when Alejandro teams up with Heather to vote him off. While taking the Drop of Shame again, Duncan happily announces to Gwen that he would be seeing her soon.
Duncan is introduced as a guest along with Owen and Courtney in Hawaiian Style, where he is reunited with Gwen. Though Courtney continues to annoy them, the couple nevertheless ignores her until Duncan loses his patience and threw a sandal at Courtney. He and Gwen then smile at each other and then share a kiss. Despite his conflict with Cody, Duncan chose to support him over Heather and Alejandro, knowing that he is the lesser evil among the final three. Unfortunately, Cody lost in the tie-breaker challenge in Hawaiian Punch and Duncan switch sides to Heather instead. When Heather is declared the winner in her ending, Duncan cheers her for defeating "La Cucaracha". Duncan is last seen swimming away from the island with the other contestants when the volcano begin to erupt.Bigger! Badder! Brutal-er!, Duncan appears on the yacht with his fellow veterans. He and Gwen are seen making out passionately while DJ, Harold, and Leshawna dance nearby.
Because of him quitting last season and thus "owing" Chris some camera time, Duncan is brought back to Camp Wawanakwa Grand Chef Auto in order to demonstrate the challenge. However, Duncan runs away once Chef unties him. As revenge for Chris using his kitchen as the site for the challenge, Chef points the newcomers to paint Mt. Chrismore, and blames it on Duncan. At Mt. Chrismore, Duncan appears and explain to Chris that it wasn't his idea to add an extra target for the contestants before revealing his true plan; detonating Chris's prize monument.
Duncan is one of seven original cast members competing the season. He is placed on the Villainous Vultures in Heroes vs. Villains along with his girlfriend, Gwen, who is unhappy to be on a team of villains. Duncan reveals in the confessional that the main purpose of his return is to be with Gwen. Although he still loves her, their relationship is beginning to strain as the season progress as Gwen keep ignoring Duncan flirting at her and even start to mock or tease him. Unknown to Duncan, Gwen is actually trying to make peace with his ex-girlfriend, Courtney, who have yet to forgive the both of them and even pretends that Duncan doesn't exist anymore.
Like many of his teammates, Duncan feels proud to be on a team of villains. In Evil Dread, he happily toast with Scott about their villain status. His relationship with Gwen continues to deteriorate with Gwen continuing to ignore him and even laugh at him after he set off a booby trap. In Saving Private Leechball, Duncan immediately realizes that Alejandro, Heather and Jo are sweet talking to Gwen in order to pull the both of them into an alliance. While he is annoyed that they spend more time arguing, he is even more annoyed that they did not try to pull him into one. Like Heather, Duncan believes that Gwen is actually being mean towards Courtney in the past episodes. When Gwen find out about his, she angrily tells him that "he does not know her at all". Duncan then realizes that Cameron is targeting Gwen and heroically jump in front of her and takes the leech for himself. Gwen is shocked to see that Duncan is able to perform a noble act, to he playfully replies her earlier statement that "she does not know him at all". After their team loses, Chris made Duncan switch teams with Courtney, as a result of their respective actions in the episode. Although frustrated with the team switch, Duncan gets up and move to the Heroic Hamsters after giving Gwen a kiss on the cheek.
Being on a team of heroes and being labeled as one greatly frustrates Duncan in Food Fright as he believes that it is affecting his image as a "bad boy". After waking up, he finds out that his team had set up a welcome party for him. In the confessional, he believes that the others are trying to make him let his guard down so that they can vote him off. Although he expresses his embarrassment and hopes his friends from juvie doesn't think of him differently, Duncan appears to be enjoying the party. Over the course of the challenge, he slowly starts to act nicer and more affectionate to people out of instinct (such as blowing kisses to Gwen and cheering on his teammates). When Mike tries to cheer him up, Duncan finds his voice familiar and believes that he might had know him somewhere before.
In the next episode, the vague familiarity of Mike's voice still bothers him. When the both of them are separated from their team, Duncan confronts Mike while he is talking to a bird affected by the Blue Harvest Moon. Sensing his suspicions, Mike pretends that Duncan might had know him from the previous season but Duncan doesn't buy it and still believes that the two of them might had met a long time ago. Before he could remember, Mike sends the bird to attack Duncan. Meanwhile, Duncan's relationship with Gwen becomes even more strained as Duncan asks her if Courtney still likes him. This continues until the end of the episode with Gwen, finally loses patience with him, breaks up with him, leaving Duncan confused about their sudden break up.
The now single Duncan still wonders why Gwen dumped him, but does not put much thought into it in No One Eggspects The Spanish Opposition; thinking that it was because he is becoming too heroic. Though he is slowly starting to accept that he is becoming a better person, he is clearly not impressed with it. Zoey (who is the closest person to him since the switch) on the other hand, is happy to see that Duncan is slowly beginning to trust her after she offers him an apple. Duncan insists that he is still a bad boy but his attempts backfire, such as when his knife breaks when he tries to carve into the wood of the confessional booth and becomes emotional when he tries to steal a mother bird's egg. At the end of the episode, Duncan finally remembers Mike as Mal, a former inmate of his from the same juvie and also a very dangerous person. Sensing that everyone is in danger, Duncan warns Zoey in the next episode. Although Zoey find it hard to believe that her boyfriend has a dangerous secret, Zoey trusts Duncan's theory not only because she had her own suspicions on Mike recently, she also believes that Duncan is being "thoughtful and considerate" much to his annoyance. For the challenge, Duncan is pitted against the mother bird from the previous episode. Refusing to hurt a defenseless animal, Duncan forfeits the challenge, making Chris and his ex-girlfriends laugh at him. During the elimination ceremony, Duncan expresses his annoyance that his team was unable to vote off Mike.
Upon reaching the merge, Duncan tries again to prove that he is a villain instead of a hero. He tries to paint a skull graffiti on the cabin wall only for Zoey to mistaken it for a bunny. He then tries to drive Chef's jeep into the lake but the engine doesn't work and by the time he is done fixing it, Chef returns and thank him for fixing his jeep. When the challenge begins, Duncan offers protection to both his exes from Mal, only for the both of them to laugh at him, as Gwen believes that Mike is one of the nicest person around. Duncan and Scott joins Zoey and Cameron on their raft as the other boats are either taken or had been sabotaged. To prove he is a "bad boy" once and for all, Duncan leaves his group in the middle of the challenge and destroys Chris's cottage. Duncan is thrilled that he might finally stop being a softie and is returning to juvie but is shocked to find out that he is going to prison instead as the cottage is private property. As he is taken away from the show, Duncan tries to sweet talk the police but no avail. The exclusive clip shows Duncan in prison, writing a letter to his mother, wishing her a happy birthday and asks her to send him a lawyer. In The Final Wreck-ening, Duncan is seen in one of the balloons, though he floats along with the others before an intern can get him down.
- View this video for Duncan's audition tape.
Duncan talks about his qualities while climbing down the wall of the juvenile hall he was staying at. But as soon as he hits the ground, he gets hit by a search light, the alarm goes off and guard dogs are heard about to approach him. Duncan then says it's been nice chatting, but he's gotta run, he then runs off into the dark. It is unknown how he was able to video tape himself climbing down the wall and then zoom out when he is caught by the guards, though it may be possible that he actually used the security cameras to film the video.waterfall.
Duncan appears to be friends with Gwen, as she has her hand on his shoulder and is smiling in the promotional art. Duncan was one of the few campers to go practically unchanged in his design, the only difference being in his facial expressions. However, Duncan is one of the few characters who had an even older draft design that looks completely different from his second and current design. The only known evidence that this was Duncan's first design is a File sheet which displays the original versions of the campers and their designated names. This design appears in the promo and is seen with Harold and Beth, but it is instead used as Cody's. This design has since been recycled into one of the interns.
- Duncan, along with Alejandro, B, and Lightning, is one of the only males with piercings on the show.
- He has the most piercings out of all characters, with six (three ear piercings, two eyebrow piercings, and a nose piercing).
- Like Trent, Justin, Alejandro, Harold, Mike, and Dave, Duncan has more than one girl attracted to him.
- Duncan is one of several contestants to have theme music dedicated to them, the others being Alejandro, Brick, Crimson, Dwayne, Ennui, Ellody Izzy, Jacques, Jay, Josee, Justin, Lindsay, Mary, Max, Mickey, most of Mike's personalities, Owen, Rock, Spud and Sugar. In Duncan's case, theme music that resembles Bad to the Bone by George Thorogood is played when Duncan first arrives to the island, and occasionally throughout the series whenever Duncan shows his tough side.
- This music is then used for Mike's alternate personality Vito.
- He is one of only eleven contestants overall to switch teams, the others being Izzy, Katie, Sierra, Brick, Jo, Scott, Courtney, Cameron, Max, and Sky.
- He is one of five characters to give the finger, the others being Leshawna, Sasquatchanakwa, Lindsay, and a beaver.
- Duncan is one of only three contestants to have been on five teams, the others being Courtney and Izzy.
- He and Courtney, however, had to return to the competition in some way to achieve this. In Duncan's case, he initially quits Total Drama World Tour before being brought back several episodes later.
- Duncan, Heather, Gwen and Zoey are the only contestants to appear in all episodes of two seasons.
- Additionally, he and Zoey are the only contestants to do so in two consecutive seasons.
- Duncan is the third contestant to be disqualified from the competition by Chris, the others being Ella, Gwen, Max, Owen, Scarlett, and Sierra.
- Duncan is one of only five contestants to compete in four seasons, the others being Courtney, Gwen, Heather, and Lindsay.
- He is also the only male to compete in four seasons.
- Duncan is one of four contestants to be eliminated before being placed on a team, the others being Geoff, Bridgette, and Blaineley.
- Duncan is confirmed to have dyed hair, with his real hair being black. This makes him one of four characters to dye their hair to an unnatural color, the others being Gwen, Max, Sierra.
- Duncan was the last member of his team in both Total Drama Island and Total Drama Action.
- Duncan is one of the seven contestants to make it to the merge in every season that they compete in. The others are Alejandro, Cameron, Mike, Owen, Scott and Zoey.
- Duncan has made the merge more times than any other contestant in the series, making it four times.
- In addition, he is one of three contestants to make it to the merge more than twice, with the others being Courtney and Owen.
- Duncan has received more symbols of immunity than any other contestant in the series. He received thirteen marshmallows in Total Drama Island, two in Total Drama All-Stars, and eight Gilded Chris Awards in Total Drama Action, making a total of twenty three.
- Duncan is responsible for the highest amount of eliminations for a non-antagonist, and the fourth highest for a contestant, having played a part in seven eliminations over the course of the series.
- Duncan had been indirectly and directly responsible for both of his girlfriends' eliminations in the first three seasons:
- In Basic Straining, Duncan's constant abuse of Harold is what caused Harold to rig the votes in order to eliminate Courtney.
- In Top Dog, Duncan voted Courtney off, after she gave him a thirty-two page letter about all of his faults, and how Duncan would have to memorize the whole letter, fix the issues, and ultimately become a "better boyfriend" to Courtney.
- Duncan is technically responsible for Gwen's elimination in Picnic at Hanging Dork. If Duncan had never thrown the dingo at Cody, then Cody would have been able to vote for Courtney and the tie-breaker between Gwen and Courtney would not occur.
- Currently, Duncan has been in the bottom two the most times with eight, in X-Treme Torture, Hide and Be Sneaky, Are We There Yeti?, Super Hero-ld, The Princess Pride, Rock n' Rule, Top Dog, and African Lying Safari.
- Duncan is the only male contestant in Total Drama All-Stars that was never exiled.
- The skull symbol on Duncan's shirt appears in several other shows made by Todd Kauffman, which includes being the band logo for Grojband in show of the same name, on the shirt of Eric Needles from Sidekick, and on the shirt of Jesse from Looped.
- According to Duncan's Total Drama World Tour contestant biography, his favorite music is Punk Rock and his favorite color is piercing silver.
- It also states that "Blood Bath 2: Summer Camp Reign of Terror" is one of his favorite movies and his favorite foods include anything you can hide a weapon in like cakes and casseroles.
- It was revealed on Total Drama Online that all of Duncan's clothes are shoplifted and that he keeps a lighter in each pocket in case he feels the urge to burn.
- As seen in Rock n' Rule, Duncan is able to play the guitar, which enables him to become a member of Der Schnitzel Kickers
- Duncan has revealed that he had owned at least three pets; a dog named Petey, a spider named Scruffy and a shared pet with Courtney, a raccoon named Brittany.
- All three of them are no longer with him as Petey ran away when he was a kid, Scruffy was killed by Harold, and Brittany is now under Courtney's custody.
- Duncan has a heart tattoo on one arm (though it is never seen again after this point). Courtney implies that he might have another, but it is never shown on-camera.
- According to the official Total Drama World Tour website, Duncan's favorite pastime is vandalism.
- As stated in Mutiny on the Soundstage, Duncan was a member of "The Muskrat Boys" earlier in life.
- Despite Duncan's tough personality and many threats, he has lost multiple physical fights that he has been in:
- He got into a fight with Leshawna in Trial by Tri-Armed Triathlon, and presumably lost, he might have also lost their arm wrestling match if he didn't cheat, as he seemed to be troubling.
- He lost a wrestling match to Courtney in Million Dollar Babies.
- He was knocked unconscious by a single blow from Harold, who is considerably scrawnier and weaker than Duncan, in Crouching Courtney, Hidden Owen.
- He was similarly knocked out by one punch from Cody in Greece's Pieces. However, Duncan was already severely injured by a bear earlier in the episode.
- He was beaten up on multiple occasions by a kangaroo in Picnic at Hanging Dork.
- He was attacked and savagely beaten by a rabid and feral Ezekiel in African Lying Safari.
- Duncan often lets his feelings for a girl get the better of him, resulting in several consequences:
- In Are We There Yeti?, Heather pretends to be weak and defenseless to him in order to steal his map. This cause him and Owen to lose and his subsequent elimination.
- In both One Million Bucks, B.C. and Million Dollar Babies, Duncan has problems fighting Courtney as he doesn't want to have their relationship ended up like Trent and Gwen. Courtney however has no problem hiding her feelings and dominates him in both episodes.
- In Get a Clue, Courtney flirts with Duncan by giving him a massage to steal his DNA. Later in the train, she encouraged him to get on top on the train, injuring him.
- In both Super Hero-ld and Rock n' Rule, he was targeted by the other contestants as eliminating him would anger Courtney
- In African Lying Safari, Heather reminded Duncan that he causes Gwen's elimination in Picnic at Hanging Dork. Duncan doesn't take this lightly and glares at her. This, however, serves as a distraction, allowing Alejandro to trip Duncan into a bush containing Serengeti Blood Berries that attracts Ezekiel to attack Duncan. He was also voted off, later in the episode.
- Duncan is the contestants that got eliminated in an abnormal way the most so far, with four occurrences.
- Duncan is the first contestant to attend an elimination ceremony of a team that he is not on, in Total Drama World Tour.
- According to Todd Kauffman, Duncan was his favorite character to design.
- Duncan appears to be left-handed, as he uses his left arm more than his right for performing his tasks (eg; holding his knife, punching).
|Interactions with||Everyone | Alejandro | Beth | Chef Hatchet | Chris | Courtney | DJ | Geoff | Gwen | Harold | Heather | Leshawna | Mike | Owen | Trent | Zoey|
|Other content||Guys' alliances | Scruffy|
|Eliminated from Total Drama Island|
|Leshawna||Are We There Yeti?||Heather|
|Finalist of Total Drama Action|
|Owen||The Aftermath: IV with Beth||N/A|
|Eliminated from Total Drama World Tour|
|N/A||Walk Like An Egyptian - Part 1||Ezekiel|
|Blaineley and Courtney||African Lying Safari||Sierra|
|Eliminated from Total Drama All-Stars|
|Sierra||You Regatta Be Kidding Me||Cameron|
|Killer Bass teammates|
|Bridgette | Courtney | DJ | Duncan | Eva | Ezekiel | Geoff | Harold | Izzy | Katie | Sadie | Tyler|
|Screaming Gaffers teammates|
|DJ | Duncan | Gwen | Harold | Heather | Leshawna|
|Team Chris Is Really Really Really Really Hot teammates|
|Alejandro | Duncan | Izzy | Noah | Owen | Sierra | Tyler|
|Villainous Vultures teammates|
|Alejandro | Cameron | Courtney | Duncan | Gwen | Heather | Jo | Lightning | Scott|
|Heroic Hamsters teammates|
|Cameron | Courtney | Duncan | Lindsay | Mike | Sam | Sierra | Zoey|