Hydra's Growth

Enchant creature
When Hydra's Growth enters, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Courage in Crisis

Put a +1/+1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Explore

You may play an additional land this turn.
Draw a card.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Snow-Covered Forest

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Nissa, Who Shakes the World

Whenever you tap a Forest for mana, add an additional {G}.
+1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land.
−8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle.

Exploration

You may play an additional land on each of your turns.

Vivien, Arkbow Ranger

+1: Distribute two +1/+1 counters among up to two target creatures. They gain trample until end of turn.
−3: Target creature you control deals damage equal to its power to target creature or planeswalker.
−5: You may reveal a creature card you own from outside the game and put it into your hand.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Scute Mob

At the beginning of your upkeep, if you control five or more lands, put four +1/+1 counters on Scute Mob.