A sort of serpent hatched from the egg of a cock. The cockatrice, aka the basilisk, had a bad eye, and its glance was fatal. Many infidels deny this creature's existence, but Semprello Aurator saw and handled one that had been blinded by lightning as a punishment for having fatally gazed on a lady of rank whom Jupiter loved.

Juno afterward restored the reptile's sight and hid it in a cave. In recent times, however, the cocks have stopped laying.