Unstable Mutation

Enchantment - Aura, U (1)
Enchant creature
Enchanted creature gets +3/+3.
At the beginning of the upkeep of enchanted creature's controller, put a -1/-1 counter on that creature.¹
Illus. Douglas Shuler

Crystal Keep Rulings Summaries

• The -1/-1 counters stay even if the enchantment is removed, and the +3/+3 goes away when the enchantment does. [D'Angelo 1994/06/01]
• Note - Also see Aura, Rule G1.30.
• Note - This card was of type "Enchant Creature" until Oracle 2005/08/01.

Format Legality	Legal in Vintage, Legacy, Extended Banned in Standard
Printings (5/31)	Time Spiral Timeshifted (Special) Fifth Edition (Common) Fourth Edition (Common) Revised Edition (Common) Arabian Nights (Common)