Urza, Lord High Artificer is a mythic Legendary Creature — Human Artificer card from Modern Horizons (MH1), collector number 75. Current market price: $17.15 (foil $19.50), TCGplayer market prices via Scryfall.
When Urza enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control." Tap an untapped artifact you control: Add {U}. {5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.