SpongeBob SquarePants - Season 5 Episode 7

Mr. Krabs enlists SpongeBob and Patrick to spy on Plankton. The pair visit Sandy for advice, who gives them a pair of laser pants. They start following Plankton and end up at the Chum Bucket, with Plankton thinking that they came to eat. While waiting for Plankton, Patrick tells SpongeBob that his laser pants are malfunctioning. As he continues trying to control them, the laser shoots out and destroys the Chum Bucket. Plankton becomes angry and attempts to destroy the Krusty Krab for revenge. However, Plankton is revealed to be Mr. Krabs, who entered into a bet with the real Plankton (who created a robot Mr. Krabs to replace the real him) to prove that if he were Plankton, he could finally steal the Krabby Patty formula.