Experiment One

Creature — Human Ooze{G}1/1

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.) Remove two +1/+1 counters from this creature: Regenerate it. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Colour identity Green · Evolve, Heal, Regenerate

In short

Experiment One has 8 listed printings; the most valuable is the Friday Night Magic printing from F13 at US$0.50 on TCGplayer's market price. Prices below are the cheapest in-stock listing in the United States.