He is a large light green worm with black eyes and a unibrow. He wears a spiky gray collar.
He appears to be a friendly worm. However, when either awoken or believes that there is a threat to the Dump, then he becomes aggressive. He enjoys playing fetch.
"The Lost Mattress"
He first appears sleeping on Mr. Krabs' mattress. Squidward, SpongeBob, and Patrick plot to try and get the mattress from him. All of their plans fail. When Mr. Krabs is awoken by the smell of his money, he joyfully reconciles with his mattress. When JK attempts to scare off Mr. Krabs, he growls and whips the mattress, making JK go flying. JK lands on Squidward's arms, who throws him down and goes running from JK, who is chasing him down the road, trying to bite him. "The Lost Mattress" ends when they go off of the screen.