Dolphin

Often cited as one of the world's most intelligent animals, dolphin cognitive abilities include complex problem-solving and tool use. Communication - Dolphin Research Center

A wild bottlenose dolphin can reach speeds of over 18 mph and launch itself 16 feet into the air.

Dolphins are perfectly adapted for life in the water, yet they retain the core characteristics of mammals: they are warm-blooded, breathe air through a blowhole, and nurse their young.