When you attach a Grass, Lightning, or Fire basic Energy card to Nidoking from your hand, Nidoking's type becomes the same type as that Energy card for the rest of the turn.
The Defending Pokémon is now Poisoned.
Flip a coin. If heads, this attack does 10 damage to each of your opponent's Benched Pokémon. If tails, this attack does 10 damage to each of your own Benched Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)