Ancient Tentacles (古代の触手, Kodai no shokushu) are humanoid beasts with tentacles on the back of their heads. Due to their appearance, they are often compared to Muscle Tentacles, but where the Ancient Tentacles differ are the moss-green skin they have, and rather than sneaking up on prey, they find the nearest boulder and throw it at prey.
Due to my lack of skill in drawing, i can't exactly show you what it would look like.