Robot SpongeBob appeared in "Welcome to the Chum Bucket" and was a robot created by Plankton to force SpongeBob make a Krabby Patty, and is confirmed as Plan B. A few months after Plankton had failed to get the secret Krabby Patty formula, he had won the card game against Mr. Krabs, reluctantly Poker, and had then won SpongeBob to work at the Chum Bucket. SpongeBob did not have the proper ingredients to cook a Krabby Patty, but he was to be treated with compassion and understanding. Later, SpongeBob became less disciplined, and called Plankton a bad name. Plankton took out his brain and put it into the Robot SpongeBob, Plankton programmed the robot to make a Krabby Patty, but then Robot SpongeBob said: Response: Why don't you ask me later?'Then Plankton yelled at him to follow his orders, but Robot SpongeBob said 'I don't wanna' and lazily drank gas soda while reading a comic book that had a comic strip of SpongeBob, and Patrick, and Squidward. Personality-wise, Robot SpongeBob is shown to be sassy and does not follow Plankton's orders to make him a Krabby Patty replying with "I don't feel like it". The robot had that response because it was still SpongeBob's brain, which has his personality, thoughts, and memories in it. Plankton just gave the brain a new body to maintain the brain which ultimately back fired which doesn't change that SpongeBob is taking advantage of Plankton. It is also shown he likes to drink oil and read comic books. Plankton becomes frustrated and puts the brain back into SpongeBob, himself.
The premise of Robot SpongeBob is similar to The Simpsons' Treehouse of Horror II segment featuring Homer's nightmare. Homer, a lazy worker, is kidnapped by Mr. Burns and Smithers, who put his brain into a robot. The robot ends up being lazy and refusing to work, just like Homer.
Part of the control panel of Glove World in Tunnel of Glove looks just like the robot.
The robot is an obvious parody of Frankenstein's Monster, because in the book/movie Dr. Frankenstein puts corpse body parts to make the monster come to life, as in here SpongeBob's brain is transferred into the robot.