Mischief

Source
This item is available from the shop or the In-Game Store for $10 or €10. It was released on December 2, 2016.

Pet Journal
This ferocious feline followed the fel forces into Azeroth during the Legion's return.

A curious kitten that followed the Legion into our world during the most recent invasion.
 * In-Game Store

Meow that's a cute kitten! - ''If you're looking for a curious cat to call your own, this fuzzy furball from Legion land would love to come home with you. Whether you're out adventuring or warming yourself by the fel fire, Mischief will be at your side, purring all the while—and definitely not plotting Azeroth’s annihilation.''
 * Blizzard Shop