It's a badger. But well done to Discovery blogger Benjamin Radford for taking the time to unpack the reasons why it's still a badger, even if it looks weird. As he says:
"...if we see a three-legged dog by the side of the road we don’t assume that it must be a previously unknown breed of three-legged dogs that science has not discovered. Instead we logically assume that the dog likely lost its leg through an accident or birth defect. Yet when it comes to other known animals with a strange appearance, people often reach for extraordinary explanations instead of logical ones."