Eggrobo

Eggrobo (エッグロボ, Eggurobo) (originally spelled EggRobo in the manual) is an egg-shaped humanoid robot resembling Dr. Robotnik. It first appeared as an enemy in the game Sonic & Knuckles, but has since then appeared in several other main games and spin-offs.

In Super Smash Flash 2
In Super Smash Flash 2, Eggrobo appears in the background of the stage Sky Sanctuary Zone, flying from one side to the other in the background. He has no impact on the game otherwise.