Nundu

The Nundu is a large East African magical beast that resembles a leopard.

Description
It moves silently despite its "gigantic" size and is considered by some to be the most dangerous creature alive. The breath of the Nundu is toxic and filled with diseases so potent that it can wipe out entire villages of people.

Nature
The Nundu is extremely hard to subdue. It has never been defeated by less than around one hundred wizards working together. Compared to the dragons used in the Triwizard Tournament, which were stunned into submission by around ten wizards, the prospect of this rare beast became truly terrifying.

History
Eldon Elsrickle owned a Nundu, which he received as a cub during a voyage to Africa to evade capture for a series of robberies he had committed. He used this Nundu to protect his home and the large treasure he had accumulated inside it from robbing other London residents with his newly-learned Unlocking Charm, keeping it subdued with a daily Stunning Spell when he was home and reviving it when he left.

However, when he found that all the houses in the neighborhood were protected by a new Anti-Alohomora Charm invented by Blagdon Blay, he was so infuriated upon returning home that he neglected to stun his Nundu and was swiftly killed by the beast.

Newton Scamander had a Nundu in his suitcase during his travels to New York in 1926. Its proximity with the heroes and the other creatures suggests that, like a lot of information on magical creatures, the information concerning the deathly breath are not totally accurate that it is not an automatic sign of death.