A bird which has a barrel-like body

Penguin, common name for 17 species of flightless seabirds widely distributed in cooler waters and along coastlines in the Southern Hemisphere. Skilled swimmers, penguins have streamlined, barrel-like bodies that reduce drag in the water. Their wings, modified to form thin, stiff flippers, provide propulsion while swimming. Unlike the bones of other birds, penguin bones are solid, not hollow, which helps them remain submerged underwater. On land penguins have a waddling gait due to their short, thick legs set far back on the body. Penguins come ashore to breed, but they are, in fact, true marine animals, spending as much as 80 percent of their lives at sea.