Lou, Higher Doppelganger

Lou, Higher Doppelganger can't be countered.
Whenever another creature enters the battlefield, you may pay {1}{g/u}{g/u}. If you do, until your next turn Lou becomes a copy of that creature and gains this ability.
{4}{u},{t}: Exile target creature an opponent controls.create a token that's a copy of that creature. Its controller draws a card.