a mythical creature, half snake and half cock, hatched from a cock's egg and able to kill with a look
O my accursed womb … A cockatrice hast thou hatched to the world, whose unavoided eye is murderous — Shakespeare
in heraldry, an animal with a dragon's tail and the body of a cock
= basilisk (1)
[Middle English cocatrice via Frenchfrom medieval Latin cocatric-, cocatrix mongoose]