Caterpiggle is an action arcade game set in a Pac-Man-like maze. Unlike Pac-Man this maze has no dots scattered around for the player to collect. Instead there are snakes moving around and the player's task as the titular creature is to eat them all. The snakes grow in size as the game goes on and if the player attacks one in the middle it will split and the two halves go in different directions. Like in Pac-Man there are guards, the Serpent Security Force, that are out to get the player. There are three of them roaming the maze and if they make contact with the player a life is lost. There is one way to take out the guards though. If the player eats a snake that a guard is touching, the guard too will get eaten. The game ends when all of the player's three lives are lost.