Aplysia fasciata
Taxonomically, the Sea Hare would more correctly be filed with the “Gastropods”, but given its slug like appearance, most people looking to identify this creature do not think of it as a snail. It is, in fact, a gastropod having an internal shell made of protein. Sea Hares can be distinguished from other Sea Slugs in that they have swimming wings.
The two protuberances on the head are sensory organs that detect chemicals in the water allowing them to find food and detect predators. They are plant eaters and their reddish to greenish color depends on the color of their food. They have a structure of tiny teeth to scrape food particles off a surface and into their mouth.
The camouflaged color of the Sea Hare, and its ability to bury itself helps protect it from predators. It also can release toxic blueish-purple ink, like an octopus. The toxin is also in their skin making them an unpleasant meal.
Live shells should never be taken from any Florida State Park.