Wistfulness is a mythic Creature — Elemental Incarnation card from Lorwyn Eclipsed (ECL), collector number 296. Current market price: $6.84 (foil $17.34), TCGplayer market prices via Scryfall.
When this creature enters, if {G}{G} was spent to cast it, exile target artifact or enchantment an opponent controls. When this creature enters, if {U}{U} was spent to cast it, draw two cards, then discard a card. Evoke {G/U}{G/U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)