One of Sunshine's star pupils, Rex King is from the United States. His special attack is called the "Jurassic Hand" with which his hand becomes a dinosaur hand. In truth, he is actually is a dinosaur and his "Jurassic Hand" is his real head and what appears to be his "head" is a fake. He and Check Mate faught Gorgeousman and Barbarian and tore Barbarian in half with his Jurassic hand. He fights Terry the Kid at the Kintestu Buffalo's Osaka Dome. He pummeled Terry the Kid with his brutal attacks, but Mantaro helped out Terry by telling chillingly bad jokes (coldness being a dinosaur's weakness). With this advantage, Terry is able to kill him.