Anatine means "duck-like" or "relating to the family of ducks." So actual ducks and their relatives may be described as anatine, and so might a person who waddles and quacks.
In zoology, anatine means "belonging to Anatidae," which is the avian family that includes waterfowl like ducks, swans, and geese. That term comes from the Latin word anas, meaning "duck." You're most likely to find this word in a biology text or a birding guide. But you might hear it in literature — for example, referring to a person's "waddling, anatine gait" or "jarring, anatine laugh": Quack-quack-quack!