The Cave Dwellers are strange, orange-brown creatures with sharp teeth, who appear in the episode "Chum Caverns" and in the game Bikini Bottom Brawlers.
Appearance
The Cave Dwellers are strange-looking creatures who appear to have a great fear of cracking whips. Their skin is orangey with brown hair. They always make awful screeching noises when they talk. Their teeth look like walrus tusks. The Cave Dwellers have light green lips.
Discovery and enslavement by Plankton
In the episode "Chum Caverns," Plankton and Karen discovered them as they attempted to dig under to the Krusty Krab. While doing so, they fell into a massive, beautiful, natural cavern populated by these beings. Plankton then enslaved these beings and made them work in his new restaurant, Chum Caverns, based on the principle that customers would be so enchanted by the scenery they wouldn't mind the horrible food. Eventually, when everyone was trapped in the underground Krusty Krab, Mr. Krabs hired one of these beings, along with Plankton, to run the cashier. It is possible that these creatures are known in Bikini Bottom, at least to Plankton, considering he said, "cave dwellers!' when he saw them, as if he knew what or who these things were.