He leads the people of Golden Island, who believe in the Meowth of Bounty. On the night that the prophecy would have been fulfilled, the night of the bone white moon, Meowth landed on the island and the people there believed that he was the Meowth of Bounty. Mikeosu worshiped Meowth, and fulfilled his every command, because he and the people thought that Meowth could bring them riches with Pay Day. However, Meowth didn't know this move.
Shimajio and Mikeosu made Meowth battle Pokémon in order to gain experience. Meowth couldn't win, but Jessie and James bailed him out by throwing James's bottle cap collection to make it appear that Meowth used Pay Day. Mikeosu and Shimajio then wanted Meowth to rule the village, but he decided to stay with Jessie and James.