The Cave Serpent is a long Elasmosaurus-like creature that has the ability to constrict its prey like a snake. It serves as an antagonist in the 1933 King Kong film.
When Kong reached to the watery canyon, a Cave Serpent went after Ann to eat her, but Kong was able to stop it, but the Serpent uses its constricting ability to kill him. Kong slams the Cave Serpent and the creature was killed instantly.
- The Cave Serpent is somehow known as Tanystropheus.
- In the colorized version, the Cave Serpent is green.