The Most Dangerous Gamer is a rare Legendary Creature — Human Gamer Guest card from Unfinity (UNF), collector number 174. Current market price: $0.26 (foil $0.34), TCGplayer market prices via Scryfall.
Deathtouch Whenever The Most Dangerous Gamer enters or attacks, open an Attraction. Whenever you open an Attraction, put a +1/+1 counter on The Most Dangerous Gamer. Whenever you claim the prize of an Attraction, destroy target permanent.