Nemesis Trap is a uncommon Instant — Trap card from Worldwake (WWK), collector number 61. Current market price: $0.21 (foil $0.39), TCGplayer market prices via Scryfall.
If a white creature is attacking, you may pay {B}{B} rather than pay this spell's mana cost. Exile target attacking creature. Create a token that's a copy of that creature. Exile it at the beginning of the next end step.