Printings
Biomass Mutation
Card Information
Type: Instant
Mana Cost: X
CMC: 2
Part of the Reserved List: No
Color Identity: 
Set: Gatecrash (GTC)
Rarity: Rare
Collector Number: 213
Oracle Text
Creatures you control have base power and toughness X/X until end of turn.
Format Legalities
Card Rulings
- January 24, 2013
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).
Source: wotc - January 24, 2013
Choosing 0 as the value for X will likely cause creatures you control to become 0/0 and be put into the graveyard.
Source: wotc
Price History
To study a single card is to glimpse the heart of a spell - a frozen moment of ambition, artistry, and arcane intent. Within each glyph lies a spark: a story untold, a duel turned, a destiny altered. Treat it not as mere parchment, dear seeker, but as a shard of the Multiverse itself.