So Thanos has task you with watching after his dog while their on vacation for five weeks ( Yes Thanos has a dog now, don't ask where he got it, you don't want to know) If anything bad happens to his dog The Earth will be destroyed. It's your job to protect this fragile little dog from danger ( what you thought it was going to be a behemoth size alien dog, nah it's just a tiny size alien tea cup dog with the anger of ten thousand hulks, but no super strength.) It's name is Snuggles / Thanos Jr.
It does have Antarctic Vibranium teeth, also it's rare, and rubbing it's tummy grant wishes while petting it's head grants immortality. So every other big bad villain is after it ( from street villains to cosmic).