Alternate-universe SpongeBob

Alternate-Universe SpongeBob is a sea sponge who usually appears as a reflection of SpongeBob since he lives in a mirror and usually goes against the laws of reflections by not following SpongeBob's movement and instead behaving in his own manner, but sometimes exists in an alternative reality as his nickname suggests. He first appears in the episode "Squid's Day Off."

"Squid's Day Off"
He appears saying, "I will destroy the Krusty Krab!" as the result of 's paranoia that will damage the Krusty Krab.

"Something Smells"
SpongeBob's breath smells so bad that made his reflection counterpart breaks the himself.

"The Algae's Always Greener"
He is the employee of Mr. Plankton in the alternate universe. He gives his boss two for bun inspection, which he takes to his office. Just as Plankton gets intimate with the burgers, SpongeBob comes into his office asking for criticism on his fry cooking skills. Plankton tells him that he is using too much sauce, which destroys SpongeBob's confidence and leads him to cry until Plankton offers him a promotion.

Later, SpongeBob panics as Mr. Krabs comes to steal the Krabby Patty secret formula, so SpongeBob serenades him with a clothes canyon until he gets a bra on Krabs, prompting him to give the patty back.

"Wet Painters"
Alternate-Universe SpongeBob is seen through ' mirror when SpongeBob tries to figure out how to prevent Mr. Krabs from seeing the paint he and got on his first dollar, but he leaves when Mr. Krabs comes home, then telling SpongeBob that he is on his own.

"Chimps Ahoy"
Patrick invents his universe with Alternate-Universe SpongeBob in it, but SpongeBob thinks it is just a mirror and points out that it was already invented. Patrick complains that someone stole his idea, with the Alternate-Universe SpongeBob responding that he thought it was a pretty good idea.

"Ghost Host"
He gets eaten by a monster as part of a long string of jokes told by the Flying Dutchman to scare SpongeBob.

SpongeBob SquarePants (clone)
SpongeBob and Alternate-Universe SpongeBob are a lot alike. However, his alternate-universe counterpart acts more dramatic than usual in "The Algae's Always Greener." Contrary to the main-universe SpongeBob, Alternate-Universe SpongeBob appears to have a bit of a rude streak; in "Wet Painters," he refuses to help SpongeBob, and in "Something Smells", he breaks the mirror he is in upon smelling SpongeBob's rancid breath, alluding to dying in a comedic way.

Patrick Star
They appear to get as Alternate-Universe SpongeBob says he thought Patrick's idea to another universe was a good idea in "Chimps Ahoy."

Trivia

 * "The Algae's Always Greener" is the only episode to feature Alternate-Universe SpongeBob without the main-universe SpongeBob.