Rex Raptor Rex Raptor , known as Dinosaur Ryuzaki in the manga and Japanese anime , is a Dinosaur Duelist . Despite his introduction as a powerful Duelist , he becomes a source of humiliation along with his companion , Weevil Underwood , after suffering defeat to Joey Wheeler , and begins considering Joey his rival for this reason . Though Rex is vindictive , arrogant , and tyrannical , he plays fairly . Design . Rex ' s character design was overseen by Kazuki Takahashi . His usual outfit consists of a green jacket and a red beanie cap , plus tan pants . In Duelist kingdom , he wears a tan vest - thing on his jacket , and a black shirt . In Battle City onward , he wears a green jacket , and a yellow shirt . His hair is brown with dyed purple strands next to his forehead . He has purple - blue eyes , whenever his irises are shown ( his pupils are usually too small to determine his eye color ) . He carries a KaibaCorp Duel Disk on his left hand . In the Waking the Dragons arc , he has a Chaos Duel Disk . In the " Yu - Gi - Oh ! The Movie " , Ryuzaki has black hair with dyed pink strands and a purple cap . Voice and mannerisms . In the original anime , Rex speaks with a Kansai accent . Etymology . " Dinosaur " is a nickname ; " Ryuzaki " is his given name . In the dub , he is named after the Tyrannosaurus Rex and the Velociraptor , 2 types of dinosaurs . Biography . Toei anime . " Yu - Gi - Oh ! The Movie " . Rex appeared in the Toei anime movie " Yu - Gi - Oh ! The Movie " , when he was seen getting up after losing to Seto Kaiba . NAS anime . " Yu - Gi - Oh ! " . Duelist Kingdom . Rex , as the Western Japan Representative , participates in the Japanese National " Duel Monsters " tournament , where he loses to Weevil Underwood in the finals . Rex was invited to the Duelist Kingdom tournament . Being a runner - up in the last tournament , he was one of the few participants given a room on the boat journey . He invited Mai Valentine to his room . Mai challenged him to a Duel , where she would give him a kiss if he won ( do anything he wants for him the Japanese Version ) , but she would get the room to herself if she wins . Confident that he wouldn ' t lose , Rex accepts . However Mai insisted that they use her cards . Unbeknownst to Rex , Mai sprayed them with different perfumes and was able to tell what cards he drew . With this advantage , Mai won and booted Rex out of the room . During the tournament , he was constantly berated by the fact Mai had more Star Chips than him . He challenged her to a Duel to get revenge but Mai , preferring to avoid him , was content to use the excuse that she had already " beaten " him once . However since Mai had previously lost to Joey Wheeler and considered it obnoxious to challenge him again , she agreed to Duel Rex , if he defeated Joey for her . During his Duel with Joey , Rex gambled " Red - Eyes Black Dragon " in the hopes of winning Joey ' s " Time Wizard " . ( In the anime , " Red - Eyes Black Dragon " was an incredibly rare card that Rex received as a prize for being a runner - up in the last tournament . ) This infuriated Mai as it would mean Rex ' s Deck would be even stronger if she had to face him . However , Joey won the Duel and he claimed Rex ' s star chips along with his " Red - Eyes Black Dragon " and his " Dragon Nails " . Battle City . In the Battle City arc , he was seen briefly , losing to Espa Roba , who cheated and had " Jinzo " crush Rex ' s " Serpent Night Dragon " . Rex then advised Joey on Roba ' s strength and left the tournament afterwards . He later observed the semifinal match between Yugi and Kaiba in Domino City , amongst other Duelists . Waking The Dragons . In the Waking the Dragons arc , it was revealed that he and Weevil lost a good deal of their popularity after the tournament and they eventually ended up wandering Domino City where they were ambushed by Gurimo . Their souls were taken , and later released when Yugi Muto defeated him . The two of them then trailed after the party until Yugi ' s soul was taken by Rafael and they begged him to take them on their Helicopter . Rafael and Alister took them to Dartz , who agreed to give them power if they passed the necessary test . Each of them was given a piece of the Orichalcos Stone and both must succeed in grasping them , which both of them did . Rex and Weevil improved their Decks by taking cards from Dartz ' s massive collection and Rex challenged Joey to a rematch . During the Duel , Joey used Rex ' s " Red - Eyes Black Dragon " against him , much to Rex ' s displeasure and anger . Despite using " The Seal of Orichalcos " Rex lost at the hands of Joey ' s " Gearfried the Swordmaster " , sending his soul to Dartz again . He was released at the end of the arc when Dartz was defeated . He and Weevil fled from the hospital they found themselves in . Sebastian Arcelus replaces Sam Regal as Rex ' s voice for this season , which is why Rex ' s voice is higher pitched than it was in seasons 1 and 2 . Grand Championship . Their next plan was to enter the KaibaCorp Grand Championship , where they both impersonated Fortune Salim . They were quickly defeated by Zigfried von Schroeder and sent back to Japan by KaibaCorp . ( In the dub , their fate after the Duel is unknown , although they were briefly seen after Yugi defeats Leon von Schroeder , possibly in Domino City , watching in disgust , indicating that they were sent back . ) Dawn of the Duel . Rex and Weevil ' s last attempt at revenge was to steal Yugi ' s Egyptian God Cards from his house , where they mistakenly grabbed Yugi ' s bag containing all of his Millennium Items . Yugi tried to stop them , but couldn ' t catch up . While examining their prize , they were sent to the Shadow Realm by Yami Bakura , who stole the Millennium Ring back from them afterwards . While Zorc ' s rampage over Ancient Egypt was in full swing , the events then were affecting the modern world as well - where Rex was shown clinging on to a pole so to not to blown away by the wind . After Zorc ' s defeat , he was also seen . Rex is shown in the last episode of Yu - Gi - Oh ! Dueling with Weevil ( cut from the dub ) . Yu - Gi - Oh ! 5D ' s . In " Yu - Gi - Oh ! 5D ' s " , a parody of him named Dinosaur Hakozaki is listed as one the Duelists defeated by Hunter Pace . Deck . Rex Raptor chiefly employs a Dinosaur Deck , focused on Dinosaur - Type monsters . His dueling strategy involves offensive Beatdown tactics , concentrating on using high ATK - powered Dinosaur monsters to bring down his opponent ' s Life Points as quickly as possible . In addition , he makes use of a confluence of Dinosaur - support Magic and Trap cards to augment on the brute power of his Dinosaurs on the dueling field . Though his signature cards are centralized around Dinosaurs , his strongest monsters tend to be Dragon - Types , such as the Red - Eyes Black Dragon , Serpent Night Dragon , and Tyrant Dragon .