Morty

Morty is a Siberian Tiger cub that is unfortunately named as, despite previous beliefs, Morty is actually a female.

Background
Stolen by Duncan from Vault 253, he gave the tiger cub to Deaphanie as a gift because he's either a nice guy or wants to get into Death's pants.

Morty is roughly over two months old, as she can still be easily held and is unable to hunt on her own, but has been weened off breast milk. Though a far cry from the fierce hunter she will grow up to be, and not formidable in any way, Morty is still good for being a cuddle pillow, emotional support, and the occasional comic relief.