Robot Plankton appears in Battle for Bikini Bottom and Truth or Square (video game).
In Battle for Bikini Bottom, he is small like Plankton and has a flying machine with gamma rays. In 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.
Battle for Bikini Bottom
- Gamma Rays
Truth or Square
In Battle for Bikini Bottom it's unknown what happens to him, since he argues with other duplicates of him that keep spawning out of the Duplicatotron 3000. In Truth or Square, he gets destroyed by SpongeBob who infiltrated him and destroyed his hearts.