Heavyweight (Poké-Body)
As long as there is a Grass Energy attached to Muk, you must pay an additional ColorlessColorless to retreat it.
Burning Sludge
Cost: Colorless, Colorless (10)
Flip a number of coins equal to the amount of Grass Energy attached to Muk. If any of them are heads, the Defending Pokémon is now Poisoned and Burned.