BlackJack's Guard Worm is a guard worm in the episode "BlackJack."
BlackJack's Guard Worm is a big light green worm, who has red eyes with black pupils and sharp, light yellow teeth. He wears a spiky metal collar attached to a chain.
SpongeBob walked up to up to BlackJack's house so he could save his parents. When he came onto the porch and approached the door, the Guard Worm reached out from a rusty boat in the backyard. He barked at SpongeBob, who is scared and says "Nice wormy."