Ob Nixilis, the Fallen

Landfall — Whenever a land you control enters, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.

Ancient Greenwarden

Reach
You may play lands from your graveyard.
If a land entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Animist's Awakening

Reveal the top X cards of your library. Put all land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap those lands.

Nissa of Shadowed Boughs

Landfall — Whenever a land you control enters, put a loyalty counter on Nissa of Shadowed Boughs.
+1: Untap target land you control. You may have it become a 3/3 Elemental creature with haste and menace until end of turn. It's still a land.
−5: You may put a creature card with mana value less than or equal to the number of lands you control onto the battlefield from your hand or graveyard with two +1/+1 counters on it.

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Solitude

Flash
Lifelink
When Solitude enters, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Hunting Grounds

Threshold — As long as seven or more cards are in your graveyard, Hunting Grounds has "Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield."

The Necrobloom

Landfall — Whenever a land you control enters, create a 0/1 green Plant creature token. If you control seven or more lands with different names, create a 2/2 black Zombie creature token instead.
Land cards in your graveyard have dredge 2. (You may return a land card from your graveyard to your hand and mill two cards instead of drawing a card.)

Sol Ring

Bone Miser

Whenever you discard a creature card, create a 2/2 black Zombie creature token.
Whenever you discard a land card, add {B}{B}.
Whenever you discard a noncreature, nonland card, draw a card.

Dark Ritual

Ayula's Influence

Discard a land card: Create a 2/2 green Bear creature token.

Bristly Bill, Spine Sower

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature.
{3}{G}{G}: Double the number of +1/+1 counters on each creature you control.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of Scute Swarm instead.

Cultivate

Ashaya, Soul of the Wild

Ashaya, Soul of the Wild's power and toughness are each equal to the number of lands you control.
Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Awakening

At the beginning of each upkeep, untap all creatures and lands.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Abundance

If you would draw a card, you may instead choose land or nonland and reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and put all other cards revealed this way on the bottom of your library in any order.

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.

Centaur Vinecrasher

Trample
Centaur Vinecrasher enters with a number of +1/+1 counters on it equal to the number of land cards in all graveyards.
Whenever a land card is put into a graveyard from anywhere, you may pay {G}{G}. If you do, return Centaur Vinecrasher from your graveyard to your hand.