This is a tree topper unlike any other! Reminiscent of a freshly made snow angel, these pteropods are actually shell-less sea snails (Clione limacina). Unlike the typical snail, they flap their adapted foot ‘wings’ to get around in the water column. They are extremely small, with the largest species reaching only 5 centimeters long. Sea angels' mostly eat their relatives, the sea butterflies, which are threatened by ocean acidification.