Eggrobo

Eggrobo, as seen in Sonic & Knuckles' Sky Sanctuary Zone.

Eggrobo is a badnik that appears in Sky Sanctuary Zone in Sonic & Knuckles. He is shaped like an egg with arms and legs (clearly made to resemble Dr. Eggman), and attacks Sonic with a laser pistol. An Eggrobo also pilots the eggpods during boss sequences when you play as Knuckles. This is because Knuckles is unaware that Eggman is the real villain, so Eggrobo is used as a stand-in.

Eggrobo is also a hidden character in Sonic R. He appears when you collect all the gold coins in Regal Ruin.

When Eggrobos appeared in the Archie-produced Sonic the Hedgehog comic book, they were referred to as "Eggbots".