Pantlaza, Sun-Favored is a mythic Legendary Creature — Dinosaur card from The Lost Caverns of Ixalan Commander (LCC), collector number 20. Current market price: $19.13 (foil $58.40), TCGplayer market prices via Scryfall.
Whenever Pantlaza or another Dinosaur you control enters, you may discover X, where X is that creature's toughness. Do this only once each turn. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)