Omnath, Locus of Unity

You may play lands from your graveyard or exile.
Landfall-When a land enters the battlefield under
your control, you may choose one that hasn't
been chosen this turn-
• Deal 4 damage to any target.
• Draw a card.
• Return a card from your graveyard to your hand.
{bull} Creatures you control gain +1/+1 and trample
until the end of the turn.