Pegasus J. Crawford/ Maximillian Pegasus is the so called owner and creator of the game Duel Monsters. He also owned the sennen/millenium eye, but it was ripped out by Bakura.In the second season, he hosted a tournament on this gigantic island, and by taking the soul of Yugi's grandfather, he forced the participation of Yugi. His plan was to take his puzzle, and take over Kaiba Corp, all in one duel. It backfired, though, when Yugi actually won the duel, and destroyd all his plans. After that, he lost his eye to Bakura, and no one really knows what happenes to him. I think he died, or something.
Insector Haga/ Weevil Underwood, is a sniveling cheat. On the way to Pegasus' tournament, he threw Yugi's Exodia cards over the side of the boat, and in the third season, he payed this guy to sneak a parasite into Jounouchi's/ Joey's deck, so he could have the upper hand. Even so, both times, he lost the duel to get the blue eyes back, and then he wasn't on top of the competition anymore, was he.
Rebecca is this little girl, and I really don't know much about her. All I know, is that she is a world renouned young duelist, and she believed that Yugi's grandfather had stolen her grandfather's Blue Eyes White Dragon, when in reality, her grandfather,(his name escapes me at the moment,)had given it to Sugoroku Muto, and later, Seto Kaiba rippes it half.*breath* She challenged him to a duel, but because he had just gotten out of the hospital, Yugi faced her in his place. Through the duel, everyone really learned that Sugoroku saved Rebecca's gramps when a shaft collapsed in an old Egyptian tomb, entrapping them both. Yugi surrendered, to prove a point, that winning is not always the most important thing.
Sugoroku Muto/Soloman Moto, is Yugi's grandfather, and the owner of the Turtle Shop, a game shop where young duelists can buy cards to pump up thier deck. His soul is stolen by Pegasus, and is later reclaimed by Yugi, using Sugoroku's deck. He is old.
Shadi is the keeper of the sennen/ millenium items, and he himself ownes two of them. The scale, and the ankh/key. He always has a glazed look on his face, mainly in his eyes, like he's being posessed. I don't know why. If anyone knows, please E-mail me and tell me.
Ryouji Otogi is the creator of Dungeon Dice Monsters, (DDM)and he idolizes Pegasus. He wanted a contract from Pegasus, but because he was incapacitated, had to wait to get it. He didn't like Yugi, and he dueled him, but according to the rules of DDM. Yugi had never even heard of the game, and he had to learn while he was dueling the creator. Even so, Yugi wiped the floor with him, and the two became friends. Otogi later got the contract he wanted. Later, his friendship with Yugi takes him to Battle city, where he helps the gang there.