Instead of having this creature attack, you may tap it to use its [Tap] ability.
[Tap]: Play rock-paper-scissors with your opponent. If you win, choose 1 of your opponent's creatures. The chosen creature gets -3000 power during this turn. (A creature with 0 or less power is destroyed.)
If the opponent reveals "paper" when you play rock-paper-scissors, your opponent chooses a card in their hand and discards it.