The Primitive Tapeworm is a tapeworm that first appears in the episode "SB-129."
The tapeworm has olive green skin, but there is some mustard yellow color mixed in. It has dark green eyes and burnt yellow patterns on its slender, flat body. It also has a small, dark green line on its back.
It first appears in the episode "SB-129," where it is swimming beside Squidward. It also briefly appears in the PC version of Lights, Camera, Pants! As the worm swims by Squidward, Squidward brushes himself off and replies, "Whoa! I guess this is before manners were invented!"