Crustoccupa
From Multiverses
Crustoccupas are organisms that live in the seas of Unda.
Physiology
Crustoccupas are soft-bodied, and have two grasping appendages that branch from the base of the mouth. Their tail is large, hard, and hinged. The two parts are concave.
Diet
These creatures eat various types of debris and flotsam floating around in the seas.
Behavior
When threatened, crustoccupas hinge their tail backwards so that, due to the tail parts' concave shape, the animal is enclosed in a hard shell that is difficult to break open.
They are very low on the food chain, and so are eaten by many other animals like Aquamorphs or Esselt.