Dinosaur Ryuzaki ( manga ) Dinosaur Ryuzaki is a character in the " Yu - Gi - Oh ! " manga . This is the original depiction of Dinosaur Ryuzaki , known as Rex Raptor , in the English anime . Ryuzaki is a powerhouse " Duel Monsters " player , whose nickname comes from his use of Dinosaur cards . He was once the runner up of the Japanese National Duel Monsters Championship and has also participated in the Duelist Kingdom and Battle City tournaments . Biography . National Championship . Ryuzaki took part in the Japanese National Duel Monsters Championship , where he made it through to the finals . There he faced Insector Haga . Ryuzaki tried to overpower his opponent with his strong Dinosaur monsters , but was defeated by Haga ' s combo plays . At some point , Ryuzaki spent a few hundred thousand yen on the card , " Red - Eyes Black Dragon " . Duelist Kingdom . Ryuzaki was invited to the Duelist Kingdom tournament . Due to his high ranking in the National Championship , he was given a luxury room for the boat ride , while other competitors had to sleep on the common room floor . On the boat , he was uninterested in Haga ' s talk of there being new rules and said there was nothing more to the game than kill or be killed . He overheard Mai Kujaku complaining about having to sleep on the common room floor and offered to let her sleep in his room . Mai took up his offer and pretended to flirt with him . While claiming she liked men stronger than her , she asked Ryuzaki if he wanted to Duel , offering to do whatever he wanted all night , if he won . Mai then began to put him off with her Aroma Tactics and asked if he still wanted to Duel , adding the condition that he would let her have the room to herself if she won . Ryuzaki accepted , but lost and was kicked out of the room . On the the island , Ryuzaki won enough Duels to have five Star Chip s . He then managed to find and confront Mai Kujaku . He got mad at her for making a fool of him on the boat and demanded another Duel . Mai was not interested in playing someone that she already beat and told him to go away . As he boasted about having five Star Chips , Mai showed him that she had eight and said she had already decided who she would get her last two from , but needed to take down another guy before that . She then got the idea to get Ryuzaki to Duel Katsuya Jonouchi and said he would Duel him if he won , thinking she could transitively beat Jonouchi that way . Ryuzaki was unhappy with doing her a favor , but agreed . Mai said that until they Dueled , Ryuzaki would be her slave . She also asked him if he knew what was " Something you can show , but can ' t see " , but regretted asking when he answered that it was the octopus in a piece of . Ryuzaki was taken to Jonouchi , who accepted the Duel and wagered two Star Chips . Ryuzaki stopped Jonouchi using his " Time Wizard " and " Baby Dragon " combo , by destroying " Baby Dragon " with " Two - Headed King Rex " on his first turn and guessed that " Time Wizard " was Jonouchi ' s face - down card . His Dinosaur s , powered by the Wasteland , overwhelmed Jonouchi ' s monsters for the first few turns . Jonouchi then used " Flame Swordsman " , whose fire - based attack weakened Dinosaurs , to dispatch of some of Ryuzaki ' s monsters . Finally Ryuzaki Summoned , " Red - Eyes Black Dragon " and defeated " Flame Swordsman " . He knew that " Time Wizard " was the only way Jonouchi stood a chance of beating " Red - Eyes " , but thought Jonouchi would not know how to use it or be too afraid to try . Ryuzaki then remembered that Jonouchi defeated Mai with " Time Wizard " and thought that if he could get it himself , he would have no problem beating Mai . He imposed an ante , saying he would get " Time Wizard " , if he won and Jonouchi would get " Red - Eyes Black Dragon " if he won . Mai objected and ordered Ryuzaki not to make the wager , but he refused to abide . However , the talk of " Time Wizard " reminded Jonouchi that he had the card face - down and Ryuzaki ' s desperation to win it made him realize it was more powerful than he considered . Jonouchi gambled and defeated Ryuzaki with the " Time Roulette " effect of " Time Wizard " . Ryuzaki was later sent home , as he did not qualify for the semifinals . Battle City . Ryuzaki took part in the Battle City tournament and Dueled Esper Roba at an early stage . Roba had his younger brothers spy on Ryuzaki ' s hand and report what cards he had , through audio equipment . Roba pretended to get this knowledge via . Ryuzaki lost the Duel , without doing any damage Roba ' s Life Points . In accordance to the ante rule , he lost his Puzzle Card and a rare card . Ryuzaki warned Jonouchi against Dueling Roba , stating that Roba could predict his opponents ' strategies and thought that since Roba beat him , Jonouchi did not stand a chance . However this encouraged Jonouchi to challenge Roba , as he felt the first step to becoming a true Duelist was to not pass up on an opponent and the second step was to fight someone stronger than oneself . When Ryuzaki saw that Jonouchi was gambling " Time Wizard " , as his rarest card , he asked what happened to " Red - Eyes Black Dragon " , still referring to it as his own card . Jonouchi corrected him , claiming ownership of the card , but said that it got stolen , because he messed up . Ryuzaki was shocked , but Jonouchi said he got the card back and his rival , referring to Dark Yugi , was holding it on to it for him . Ryuzaki and the other spectators laughed at Jonouchi , for trying to Summon " Giltia the D . Knight " , without Sacrifice , and thinking it got destroyed by ESP , when it did not work . The Dark Side of Dimensions . He appeared among the crowd at Kaiba Land , during the Duel Disk exhibition Duel . He , along with the rest of the crowd , disappeared thanks to a distorted Aigami , but returned along with everyone else when Aigami was reverted to normal . Deck . Ryuzaki uses an aggressive Dinosaur Deck . He was not shown using anything other than Monster Card s . One of Ryuzaki ' s cards is unnamed . Duels . Ryuzaki took part in the following Duels .