Acromantula

Acromantulas are giant, venomous spiders belonging to the world of Harry Potter, and now they were introduced to real life Earth. Formerly dangerous and possessing a (formerly) voracious appetite (which it has, when brought to real life Earth, they are now possessing an omnivorous appetite), they are described as one of the (formerly) deadliest monsters to ever inhabit the world.

Nowadays, they are no longer deadly, and are friendly to humans, dylanuses and other sapient species, except vampires.