Octillery (PL #58)

Any time the Defending Pokémon tries to attack, your opponent flips a coin. If tails, that attack does nothing. (If the Defending Pokémon is no longer your opponent's Active Pokémon, this effect ends.)

Reveal the top 5 cards of your deck. Flip a coin for each Energy card you find there. This attack does 50 damage times the number of heads. Shuffle the revealed cards back into your deck.