Dragonfly
Most of a dragonfly's life is spent in the nymph form, beneath the water's surface. It is quite active. It can extend its jaws in front of its mouth to catch prey. Tiny vertebrates such as tadpoles and fish are part of its diet. Some nymphs even hunt on land. They draw water in and out of their rectum. They can move fast by squirting water out of the anus.  They also have gills in their rectum.