Biomass Mutation
Current paper retail
Card Kingdom$0.49
Cardmarket€0.24
ManaPool$0.25
TCGplayer$0.39
Buylist (dealers pay)
Card Kingdom$0.03
90-day paper retail (USD)
3 providers
This printing
SetPLST
Collector #GTC-213
Released2021-04-24
Rarityrare
ArtistDan Murayama Scott
LanguageEN
Layoutnormal
AttributesReprint
ScryfallOpen ↗

Biomass Mutation

RareColour IDMV 2
Instant
Creatures you control have base power and toughness X/X until end of turn.
Card capabilities
Instant
Derived deterministically from card types, Oracle text and keywords. Not a strategic evaluation.
Format legality
Other printings
Rulings (2)
wotc24 Jan 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).
wotc24 Jan 2013
Choosing 0 as the value for X will likely cause creatures you control to become 0/0 and be put into the graveyard.