A cockatrice is a mythical beast, essentially a two-legged dragon 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.
The cockatrice was first described in its current form in the late fourteenth century.
The Oxford English Dictionary gives a derivation from Old French cocatris, from medieval Latin calcatrix, a translation of the Greek ichneumon, meaning tracker. The twelfth century legend was based on a reference in Pliny's Natural History that the ichneumon lay in wait for the crocodile to open its jaws for the trochilus bird to enter and pick its teeth clean. An extended description of the cockatriz by the 15th-century Spanish traveller in Egypt, Pedro Tafur, makes it clear that this refers to the Nile crocodile.
According to Alexander Neckam's De naturis rerum (ca 1180), the cockatrice was the product of an egg laid by a cock (a male chicken) and incubated by a toad; a snake might be substituted in re-tellings. Cockatrice became seen as synonymous with basilisk when the basiliscus in Bartholomeus Anglicus' De proprietatibus rerum (ca 1260) was translated by John Trevisa as cockatrice (1397). A basilisk, however, is usually depicted without wings.