Whim of Volrath is a rare Instant card from Tempest (TMP), collector number 102. Current market price: $8.19, TCGplayer market prices via Scryfall.
Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.) Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another until end of turn. (For example, you may change "nonred creature" to "nongreen creature" or "plainswalk" to "swampwalk.")