Cockatrice

A cockatrice overdoor at Belvedere Castle (1869) in New York's Central Park.

A cockatrice is a mythical beast, essentially a two-legged dragon, wyvern, or serpent-like creature with a rooster's head. Described by Laurence Breiner as "an ornament in the drama and poetry of the Elizabethans", it was featured prominently in English thought and myth for centuries. They are created by a chicken egg hatched by a toad or snake.