"A cockatrice is a legendary creature, resembling a large rooster with a lizard-like tail, "an ornament in the drama and poetry of the Elizabethans" Laurence Breiner described it; "the cockatrice, which no one ever saw, was born by accident at the end of the twelfth century and died in the middle of the seventeenth, a victim of the new science". The cockatrice was first described in the late twelfth century based on a hint in Pliny's Natural History as a duplicate of the basilisk or regulus, though, unlike the basilisk, the cockatrice has wings. According to Alexander Neckam's De naturis rerum (ca 1180), it was supposed to be born from an egg laid by a cock and incubated by a toad; a snake might be substituted in re-tellings. "
source is wikipedia cuz I'm lazy!