Toxrill, the Corrosive - [Foil] Innistrad: Double Feature (DBL) VOW where X is the amount

where X is the amount of mana spent to cast it

Each opponent can't draw more than one card each turn

first strike Whenever this creature mutates

then return it to the battlefield tapped under its owner's control

if you control your commander

Toxrill, the Corrosive - [Foil] Innistrad: Double Feature (DBL) VOW where X is the amountAt the beginning of each end step, put a slime counter on each creature you don't control. Creatures you don't control get 1 1 for each slime counter on them. Whenever a creature you don't control with a slime counter on it dies, create a 1 1 black Slug creature token. {U}{B}, Sacrifice a Slug: Draw a card.