Biomass Mutation

Duskmourn: House of Horror Commander (DSC) #214 · Rare · Instant

Mana cost: {X}{G/U}{G/U}

Creatures you control have base power and toughness X/X until end of turn.

"A regression to ancient forms? A glimpse of future evolutions? Or a fleeting alteration of the present?"
—Vorel of the Hull Clade

Illustrated by Dan Murayama Scott · Released September 27, 2024

Prices

Nonfoil price since August 25, 2026: up $0.07 USD (38.9%) to $0.25 USD; low $0.18 USD, high $0.25 USD.

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2013-01-24 · wotc — Biomass Mutation overwrites any effects that set the power and/or toughness of a creature you control to a specific value. Effects that modify power and/or toughness but don't set them to a specific value (like the one created by Giant Growth), power/toughness changes from counters, and effects that switch a creature's power and toughness will continue to apply. For example, say you control a 1/1 creature that's getting +4/+2 from an Aura, has a +1/+1 counter on it, and is affected by an effect that switches its power and toughness. This creature is 4/6. If you cast Biomass Mutation with X equal to 4, the creature would become 7/9 (4/4, +4/+2 from the Aura, +1/+1 from the counter, then switch power and toughness).
2013-01-24 · wotc — Choosing 0 as the value for X will likely cause creatures you control to become 0/0 and be put into the graveyard.