Walking Ballista

Walking Ballista enters the battlefield with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Tribal Unity

Creatures of the creature type of your choice get +X/+X until end of turn.

Ant Queen

{1}{G}: Create a 1/1 green Insect creature token.

Constant Mists

Buyback—Sacrifice a land. (You may sacrifice a land in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Prevent all combat damage that would be dealt this turn.

Magus of the Candelabra

Seek the Horizon

Search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Chimeric Staff

{X}: Chimeric Staff becomes an X/X Construct artifact creature until end of turn.

Exploration

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

Burgeoning

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

Rites of Flourishing

At the beginning of each player's draw step, that player draws an additional card.
Each player may play an additional land on each of their turns.

Regrowth

Return target card from your graveyard to your hand.

Rocket Launcher

{2}: Rocket Launcher deals 1 damage to any target. Destroy Rocket Launcher at the beginning of the next end step. Activate only if you've controlled Rocket Launcher continuously since the beginning of your most recent turn.

Hangarback Walker

Hangarback Walker enters the battlefield with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

Wolfbriar Elemental

Multikicker {G} (You may pay an additional {G} any number of times as you cast this spell.)
When Wolfbriar Elemental enters the battlefield, create a 2/2 green Wolf creature token for each time it was kicked.

Gelatinous Genesis

Endless One

Endless One enters the battlefield with X +1/+1 counters on it.

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.

Shield of the Ages

{2}: Prevent the next 1 damage that would be dealt to you this turn.

Soul's Majesty

Draw cards equal to the power of target creature you control.

Forest

Boundless Realms

Search your library for up to X basic land cards, where X is the number of lands you control, put them onto the battlefield tapped, then shuffle.

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When Hydra Broodmaster becomes monstrous, create X X/X green Hydra creature tokens.

Snake Basket

{X}, Sacrifice Snake Basket: Create X 1/1 green Snake creature tokens. Activate only as a sorcery.

Sasaya's Essence

Whenever a land you control is tapped for mana, add an additional one mana of any type that land produced for each other land you control with the same name as it.

Sasaya, Orochi Ascendant

Reveal your hand: If you have seven or more land cards in your hand, flip Sasaya, Orochi Ascendant.

Sasaya, Orochi Ascendant // Sasaya's Essence

Elvish Fury

Buyback {4} (You may pay an additional {4} as you cast this spell. If you do, put this card into your hand as it resolves.)
Target creature gets +2/+2 until end of turn.

Hurricane

Hurricane deals X damage to each creature with flying and each player.

Soul of Zendikar

Reach
{3}{G}{G}: Create a 3/3 green Beast creature token.
{3}{G}{G}, Exile Soul of Zendikar from your graveyard: Create a 3/3 green Beast creature token.

Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.