Tawnos, Urza's Apprentice is a mythic Legendary Creature — Human Artificer card from The List (PLST), collector number C18-45. Current market price: $0.50, TCGplayer market prices via Scryfall.
Haste {U}{R}, {T}: Copy target activated or triggered ability you control from an artifact source. You may choose new targets for the copy. (Mana abilities can't be targeted.)