Leech

From Earth Central

An extremely dangerous native lifeform of Spatterjay, Leeches are the dominant predators on land and hold a similar position in the ocean. They are one of the few organisms that cannot be infected by the Spatterjay virus, and produce Sprine, its only known antidote. The largest leeches can grow up to thirty metres in length, and are a serious threat even to Hooper vessels.

Some xenobiologists believe that leeches may eventualyl eradiacate all other native life-forms on Spatterjay.