Muxus, Goblin Grandee is a mythic Legendary Creature — Goblin Noble card from Secret Lair Drop (SLD), collector number 2833. Current market price: $48.99 (foil $78.99), TCGplayer market prices via Scryfall.
When Muxus enters, reveal the top six cards of your library. Put all Goblin creature cards with mana value 5 or less from among them onto the battlefield and the rest on the bottom of your library in a random order. Whenever Muxus attacks, it gets +1/+1 until end of turn for each other Goblin you control.