Meganium ex

Once during your turn (before your attack), you may attach a Grass Energy card from your hand to 1 of your Pokémon. If you do, remove 1 damage counter from that Pokémon. This power can't be used if Meganium ex is affected by a Special Condition.

Power Poison

90

Discard 1 Energy attached to Meganium ex. The Defending Pokémon is now Poisoned.