Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Swamp

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Thriving Grove

Thriving Grove enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Iridescent Hornbeetle

At the beginning of your end step, create a 1/1 green Insect creature token for each +1/+1 counter you've put on creatures under your control this turn.

Thriving Isle

Thriving Isle enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Thriving Moor

Thriving Moor enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Counterspell

Sporocyst

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Defender
Spore Chimney — When Sporocyst enters, search your library for up to X basic land cards, put them onto the battlefield tapped, then shuffle.

Repeal

Return target nonland permanent with mana value X to its owner's hand.
Draw a card.

Pridemalkin

When Pridemalkin enters, put a +1/+1 counter on target creature you control.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Contortionist Troupe

Contortionist Troupe enters with X +1/+1 counters on it.
Coven — At the beginning of your end step, if you control three or more creatures with different powers, put a +1/+1 counter on target creature you control.

Termagant Swarm

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Death Frenzy — When Termagant Swarm dies, create a number of 1/1 green Tyranid creature tokens equal to Termagant Swarm's power.

Wildwood Scourge

This creature enters with X +1/+1 counters on it.
Whenever one or more +1/+1 counters are put on another non-Hydra creature you control, put a +1/+1 counter on this creature.

Cultivate

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.

Sea Gate

Sea Gate enters tapped.
As Sea Gate enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Quandrix Campus

Quandrix Campus enters tapped.
{T}: Add {G} or {U}.
{4}, {T}: Scry 1.

Ivy Elemental

Ivy Elemental enters with X +1/+1 counters on it.

Pull from Tomorrow

Gang Up

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.)
Destroy target creature with power X or less.

Haunted Mire

({T}: Add {B} or {G}.)
Haunted Mire enters tapped.

Golgari Guildgate

This land enters tapped.
{T}: Add {B} or {G}.

Black Dragon Gate

Black Dragon Gate enters tapped.
As Black Dragon Gate enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Silver Scrutiny

You may cast Silver Scrutiny as though it had flash if X is 3 or less.
Draw X cards.

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Condescend

Counter target spell unless its controller pays {X}. Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Arcane Signet

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

Foul Orchard

Foul Orchard enters tapped.
{T}: Add {B} or {G}.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on it.

Zaxara, the Exemplary

Deathtouch
{T}: Add two mana of any one color.
Whenever you cast a spell with {X} in its mana cost, create a 0/0 green Hydra creature token, then put X +1/+1 counters on it.

Hydroid Krasis

When you cast this spell, you gain half X life and draw half X cards. Round down each time.
Flying, trample
Hydroid Krasis enters with X +1/+1 counters on it.

Sol Ring

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
Mistcutter Hydra enters with X +1/+1 counters on it.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters with X +1/+1 counters on it.

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Stumpsquall Hydra

When Stumpsquall Hydra enters, distribute X +1/+1 counters among it and any number of commanders.

The Goose Mother

Flying
The Goose Mother enters with X +1/+1 counters on it.
When The Goose Mother enters, create half X Food tokens, rounded up.
Whenever The Goose Mother attacks, you may sacrifice a Food. If you do, draw a card.

Sweep the Skies

Converge — Create a 1/1 colorless Thopter artifact creature token with flying for each color of mana spent to cast this spell.

Kurbis, Harvest Celebrant

Kurbis, Harvest Celebrant enters with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.
Remove a +1/+1 counter from Kurbis: Prevent all damage that would be dealt this turn to another target creature with a +1/+1 counter on it.

Manor Gate

Manor Gate enters tapped.
As Manor Gate enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Island

Vastwood Hydra

Vastwood Hydra enters with X +1/+1 counters on it.
When Vastwood Hydra dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra among any number of creatures you control.

Helm of Awakening

Mind Grind

Each opponent reveals cards from the top of their library until they reveal X land cards, then puts all cards revealed this way into their graveyard. X can't be 0.

Forest

Branching Evolution

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Endless One

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

Hooded Hydra

Hooded Hydra enters with X +1/+1 counters on it.
When Hooded Hydra dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As Hooded Hydra is turned face up, put five +1/+1 counters on it.

Nylea's Intervention

Choose one —
• Search your library for up to X land cards, reveal them, put them into your hand, then shuffle.
• Nylea's Intervention deals twice X damage to each creature with flying.

Feral Hydra

Feral Hydra enters with X +1/+1 counters on it.
{3}: Put a +1/+1 counter on Feral Hydra. Any player may activate this ability.

Clash of Wills

Counter target spell unless its controller pays {X}.

Disembowel

Destroy target creature with mana value X.

Gargos, Vicious Watcher

Vigilance
Hydra spells you cast cost {4} less to cast.
Whenever a creature you control becomes the target of a spell, Gargos, Vicious Watcher fights up to one target creature you don't control.

Honest Rutstein

When Honest Rutstein enters, return target creature card from your graveyard to your hand.
Creature spells you cast cost {1} less to cast.

Corpsejack Menace

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on it instead.

Command Tower

Wren's Run Hydra

Reach
Wren's Run Hydra enters with X +1/+1 counters on it.
Reinforce X—{X}{G}{G} ({X}{G}{G}, Discard this card: Put X +1/+1 counters on target creature.)