Omnath, Locus of Creation

When Omnath, Locus of Creation enters the battlefield, draw a card.
Landfall — Whenever a land enters the battlefield under your control, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add {R}{G}{W}{U}. If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters the battlefield tapped.
Whenever a Mountain enters the battlefield under your control, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.