Ixil, the Beastlord

Trample, Vigilance, Indestructible
Each other creature with power 4 or greater has
+X/+X, trample and vigilance, where X is its
power.
{2}{g}{r}{w}: Search your library for a creature card
with power X or less, where X is the greatest
power among creatures you control, and exile it.
You may cast it without paying its mana cost until
end of turn, and you may cast it as if it
had flash.