Robot Plankton is a giant robot who appears in SpongeBob's Truth or Square video game.
In SpongeBob's Truth or Square, he is gray and giant and is apparantely part of the Chum Bucket itself. One of his hands is a cannon. The other he just uses to smash stuff with.
In SpongeBob's Truth or Square he gets destroyed by SpongeBob who infiltrated him and destroyed his hearts.