hey, check out this wonderful ocean animal the prickly SEA URCHIN:

Sea Urchins are typically spiny, globular animals, echinoderms in the class Echinoidea. The Sea Urchin is found across the ocean floors worldwide, but rarely in the colder, polar regions. Sea Urchins are commonly found along the rocky ocean floor in both shallow and deeper water and are also commonly found inhabiting coral reefs.

Sea Urchin