The Primitive Tapeworm appears in the episode, "SB-129."
The tapeworm has olive green skin, but there is some mustard yellow 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 appears in the episode "SB-129," swimming beside Squidward, and briefly 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!"