Dr. Robotnik is a Teletubby who only appeared in Sonic the derphog: Eggventure (GET IT!?). Near the end of the video, Dr. Robotnik the Teletubby confronts Eggman while he is watching Eggbot 2.0 attack Peach's Castle, only for Eggman to get scared and throw Dr. Robotnik the Teletubby into Eggbot 2.0, causing the huge robot to change its nuclear missile launching timer to 5. He later appears at the end of the blooper after Sonic is told that he saved the world, in front of the screen.
He looks like Laa-Laa only yellowish-green (though this might just be due to the stage lighting). He has a crowbar, wears a white hat and Dr. Eggman's glasses in purple, and also has a moustache.