The cave monster is a monster who first makes a cameo appearance in the episode "Your Shoe's Untied."
The monster is lime green, with light green lips. He has numerous tentacles that allow him to move. He has a short amount of hair on his back. He has a large amount of eyes in one area, with lids all differing in colors. He has one large blowhole on the top of his head, of which he shot SpongeBob out of.
The cave he was residing in was relatively small and an obvious problem for him, which can be noted by the stretch marks on the side of his body, caused by attempting to squeeze through the opening.
Role in series
"Your Shoe's Untied"
He eats SpongeBob after he asks him if he knows how to tie his shoes. In the monster's mouth, SpongeBob asks a human skeleton with fishing gear if he knows how to tie his shoes. Afterwards, the monster shoots him out of a blowhole.