Basilisks

Basilisk is a legendary reptile said to be king of serpents. It has the power of causing death by a single glance. It is described to look like either a huge lizard, or giant snake, or a cockerel with a snake's tail and teeth. Stories gradually added to deadly capabilities of the basilisk. Some writers said it could kill not only by touch, but also by touching something that is touching the victim, and its breath so toxic, that will also cause immediate death.

Exemplary fantasy books with basilisks:

Harry Potter
The adventures of Harry Potter can make you move from boring muggle reality into the world of magic, perfectly disguised from common mortals, awaiting for... Books: Goblet of Fire | Prisoner of Azkaban | Deathly Hallows

Lords of Dus
Books: Lure of the Basilisk | Book of Silence | Seven Altars of Dusarra