EggRobo

An EggRobo (エッグロボ, Eggurobo ?) is an egg-shaped humanoid robot which resembles Doctor Eggman. They first appeared as enemies in the game Sonic & Knuckles. In Sonic's storyline, they only appeared as standard enemies in the Sky Sanctuary Zone. In Knuckles' story, however, one EggRobo in particular replaces Eggman as the end-of-zone boss in a number of levels.

An EggRobo later appears in Sonic R as a playable character, and in the form of a kart racer in Sonic Adventure 2.