Igglybuff

Pokémon Power: Gaze Once during your turn (before your attack), choose 1 of your opponent's Benched Pokémon that has a Pokémon Power. That power stops working until the end of this turn. This effect ends if that Pokémon leaves the Bench.

If this Baby Pokémon is your Active Pokémon and your opponent tries to attack, your opponent flips a coin (before doing anything required in order to use that attack). If tails, your opponent's turn ends.