Many of you may not know about Evil Otto unless you are familiar with the Atari game Berzerk.
The function of Evil Otto, represented by a bouncing smiley face, is to quicken the pace of the game. Otto is unusual, with regard to games of the period, in that there is no way to kill him. Otto can go through walls with impunity and is attracted to the player character. If robots remain in the maze Otto moves slowly, about half as fast as the humanoid, but he speeds up to match the humanoid’s speed once all the robots are killed. Evil Otto moves exactly the same speed as the player going left and right but he can move faster than the player going up and down; thus, no matter how close Otto is, the player can escape as long as they can avoid moving straight up or down.