Guardian Ape

Vigilance, Trample, Menace, Reach

You may cast Guardian Ape without paying its neutral mana cost if you removed X counters from creatures you control and Y counters from creatures you don't control this turn, where X - Y has to be 5. Alternatively, you may reduce the mana cost to cast Guardian Ape by {1} for each such difference between X and Y (up to a maximum reduction of {5}).

When Guardian Ape dies, you may pay {5}{b/g}. If you do, return it to the battlefield transformed under your
control.