Evil Otto

You may not remember his name, but you certainly remember his face. That's all there is to remember, actually. Patience definitely was not a virtue in Berzerk, the arcade quarter-muncher that gave children of the '80s nightmares about springy smiley faces. Just when you were doing great, taking your time to line up every shot so you could send the evil robots to the great scrapheap in the sky, along came Evil Otto, taunting you with his perverted smile. He would bounce toward you like a giddy-yet-nefarious rubber ball of death. Making matters worse, the indestructible Otto was relentless in his pursuit, and your only escape was to run to another robot-filled room.

According to The Winner's Book Of Videogames by Craig Kubey, Alan MacNeil, the designer of Berzerk for Stern Electronics, created Evil Otto as a game villain because he hated smiley faces.