Omochao (オモチャオ Omochao?) is a robotic Chao with a propeller on its head. Its name is a portmanteau of the Japanese word omocha, meaning "toy", and Chao. In some games he is renamed Robochao in English, but he is always called Omochao in Japanese.
Omochao is featured in the games Sonic Adventure and Sonic Adventure 2 for Sega Dreamcast, Sonic Adventure DX, Sonic Adventure 2 Battle for the GameCube, Sonic Pinball Party, Sonic Battle, and Sonic Advance 3, for the Game Boy Advance, and the multi-console games Sonic Heroes, Shadow the Hedgehog, Sonic Riders, Mario And Sonic At The Olympic Winter Games, Sonic Free Riders, and Sonic Generations. He also appears as a guide in Sonic and the Secret Rings' Party Mode menu.