The basilisk is a legendary monster that was said to have the power to kill with its stare. It is created from the egg of a snake or toad, hatched by a cockerel. This is the reverse of the cockatrice, which was said to be hatched from a cockerel’s egg, hatched by a snake or toad. It is usually depicted as a reptile with a cockerel’s crest or head.
The basilisk appears in Harry Potter and the Chamber of Secrets as a giant serpent with a lethal stare.