The Odiferous Basilisk                                

Inspired by the Greek Medusa myth, the Basalisk was a horrible winged reptile, said to be the king of serpents, able to kill anyone approaching merely by looking at him.  The Basalisk is also able to kill birds in flight by its ghastly odor.  But the creature can be killed by holding a mirror in front of it.  It dies by looking at itself.  Another death threat for this beast is having it hear the crow of a rooster.