In SpongeBob's Truth or Square, he is light gray and giant and is apparently part of the Chum Bucket itself. One of his hands is a cannon. The other he just uses to smash stuff with.
The PlanktoBot has an ability to shoot pellets from its machine gun hand, spitting robots out from its mouth and trying to smack SpongeBob with its fist (which allow SpongeBob to smack it, causing the giant robot's mouth to open and allow SpongeBob to went inside).
SpongeBob's Truth or Square
PlanktoBot is the final boss in the game. This version of the mech is built into the Chum Bucket, and thus, is Gigantic, unlike the Battle for Bikini Bottom version. The robot is not fought directly, like the other robots, and is instead fought from inside.
Plankton originally uses this robot to attack Krusty Krab after SpongeBob says that he put the formula in the safe. However, when the robot's antennas are raised, it accidentally being set to attack Bikini Bottom, not Krusty Krab.
The PlanktoBot is destroyed after SpongeBob goes inside its head and destroy its core.