Whiplash Trap is a common Instant — Trap card from Duel Decks: Speed vs. Cunning (DDN), collector number 70. Current market price: $0.19, TCGplayer market prices via Scryfall.
If an opponent had two or more creatures enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost. Return two target creatures to their owners' hands.