Metamorphic Ooze

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Remove X +1/+1 counters from Metamorphic Ooze: Metamorphic Ooze becomes a copy of target creature with converted mana cost X or less. (This effect lasts indefinitely.)