Wryneck

A twisted or distorted neck; a deformity in which the neck is drawn to one side by a rigid contraction of one of the muscles of the neck; torticollis.

Any one of several species of Old World birds of the genus Jynx, allied to the woodpeckers; especially, the common European species (J. torguilla); -- so called from its habit of turning the neck around in different directions. Called also cuckoo's mate, snakebird, summer bird, tonguebird, and writheneck.

Old World woodpecker with a peculiar habit of twisting the neck

an unnatural condition in which the head leans to one side because the neck muscles on that side are contracted