The ice cream cone or trumpet worm is a marine animal stuck to the ocean floor. The odd-looking worm constructs a tube to live in by gluing together sand and shell fragments. 

The tube expands as the worm grows and eventually looks like an ice cream cone, hence its name. The weird ice cream cones are about 3 inches long and open on both sides.

Another name for the ice cream cone worm is trumpet worm because of its tube shape.