Simic Aristocrat

Flying, 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.)
{u}{g}, {t}, Remove X +1/+1 counters from a creature you control: Search your library
for a creature card with converted mana cost X or less, reveal it, and put it into your hand. Then shuffle your library.