The short answer is nothing
The three largest grading companies for Pokmon cards are: PSA (Professional Sports Authenticator) Beckett Grading Services (BGS) CGC (Certified Guaranty Company) Although they all grade cards, they differ in reputation, system, and market value
It's partially based off the Japanese expansion Night Wanderer
While the card on its own is not as scary, the Taomon Loop deck is a thing that can constantly play out multiple Taomon cards with cards like Kaiser Nail or the alternate Digivolution, Kazuhamon
Like most Pokmon cards, the value of Swinub depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Neo Genesis)
What are the weaknesses and retreat cost of this Larvitar card