Basilisk

n.
  1. A fabulous serpent, or dragon. The ancients alleged that its hissing would drive away all other serpents, and that its breath, and even its look, was fatal. See Cockatrice.
  2. (Zoöl.) A lizard of the genus Basiliscus, belonging to the family Iguanidæ.
  3. (Mil.) A large piece of ordnance, so called from its supposed resemblance to the serpent of that name, or from its size.

This genus is remarkable for a membranous bag rising above the occiput, which can be filled with air at pleasure; also for an elevated crest along the back, that can be raised or depressed at will.