The gorilla is a man in a gorilla suit who first appears in the episode "I Had an Accident."
He appeared disguised as Patrick Star and stuffed the real Patrick and Sandy into a bag, and smacked them on the ground and stomped on them, which made SpongeBob finally go outside. He also hangs out with George, and they most likely are friends. When SpongeBob asked what the gorilla was doing underwater in the first place, the gorilla panicked and fled on George before they could question him any further, leaving everybody confused. The Gorilla also appears in the episode "Friend or Foe" in the live action Patchy the Pirate segments, as Patchy's replacement at The Poop Deck. He is apparently a better cook than Patchy, but after Patchy calls the gorilla "a smelly, hairy fleabag", the gorilla starts throwing food at Patchy. The Gorilla Suit makes a brief appearance in "SpongeBob's Last Stand" during the song Give Jellyfish Fields a Chance. However, the Gorilla Suit in this episode is animated, unlike in its other appearances where it is not animated. Also, the Gorilla suit head makes a quick appearance in "Shell Shocked," as one of the option's for Gary's new shell after it cracks