Giovanni's Nidoking MODG2 7

If the Defending Pokémon's maximum HP is 50 or less, it can't attack Giovanni's Nidoking during your opponent's next turn. (Benching or evolving either Pokémon ends this effect.)

Flip a coin. If heads, this attack does 40 damage plus 30 more damage; if tails, this attack does 40 damage.