Flip a coin. If heads, the Defending Pokémon is now either Asleep, Confused, Paralyzed, or Poisoned (your choice).

Does 10 damage times the number of Energy attached to the Defending Pokémon. After doing damage, remove a number of damage counters from Butterfree equal to the amount of damage done to the Defending Pokémon (after applying Weakness and Resistance).