Pokémon Power: Energy Drain
If an opponent's attack does damage to Koga's Muk (even if Koga's Muk is Knocked Out), flip a coin. If heads and if it has any, choose 1 Energy card attached to the attacking Pokémon and discard it. This power can't be used if Koga's Muk is already Asleep, Confused, or Paralyzed when your opponent attacks.