Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

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.

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Simic Signet

Hooded Hydra

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Kiora, Behemoth Beckoner

Whenever a creature you control with power 4 or greater enters, draw a card.
−1: Untap target permanent.

Ring of Kalonia

Equipped creature has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's green.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Oran-Rief Hydra

Trample
Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature. If that land is a Forest, put two +1/+1 counters on this creature instead.

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Whispersilk Cloak

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

Rabid Bite

Target creature you control deals damage equal to its power to target creature you don't control.

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.

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.

Finale of Revelation

Draw X cards. If X is 10 or more, instead shuffle your graveyard into your library, draw X cards, untap up to five lands, and you have no maximum hand size for the rest of the game.
Exile Finale of Revelation.

Uncage the Menagerie

Search your library for up to X creature cards with different names that each have mana value X, reveal them, put them into your hand, then shuffle.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Harmonize

Mind Spring

Vastwood Hydra

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

Thassa's Intervention

Choose one —
• Look at the top X cards of your library. Put up to two of them into your hand and the rest on the bottom of your library in a random order.
• Counter target spell unless its controller pays twice {X}.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Island

Primordial Hydra

This creature enters with X +1/+1 counters on it.
At the beginning of your upkeep, double the number of +1/+1 counters on this creature.
This creature has trample as long as it has ten or more +1/+1 counters on it.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Arcane Signet

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

Polukranos, Unchained

Polukranos enters with six +1/+1 counters on it. It escapes with twelve +1/+1 counters on it instead.
If damage would be dealt to Polukranos while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from it.
{1}{B}{G}: Polukranos fights another target creature.
Escape—{4}{B}{G}, Exile six other cards from your graveyard.

Dregs of Sorrow

Destroy X target nonblack creatures. Draw X cards.

Golgari Guildgate

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

Heroes' Bane

This creature enters with four +1/+1 counters on it.
{2}{G}{G}: Put X +1/+1 counters on this creature, where X is its power.

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.

Unbound Flourishing

Whenever you cast a permanent spell with a mana cost that contains {X}, double the value of X.
Whenever you cast an instant or sorcery spell or activate an ability, if that spell's mana cost or that ability's activation cost contains {X}, copy that spell or ability. You may choose new targets for the copy.

Command Tower

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Sol Ring

Tranquil Thicket

This land enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

Golgari Signet

Scourge of Skola Vale

Trample
This creature enters with two +1/+1 counters on it.
{T}, Sacrifice another creature: Put a number of +1/+1 counters on this creature equal to the sacrificed creature's toughness.

Coiling Oracle

When this creature enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Pemmin's Aura

Enchant creature
{U}: Untap enchanted creature.
{U}: Enchanted creature gains flying until end of turn.
{U}: Enchanted creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
{1}: Enchanted creature gets +1/-1 or -1/+1 until end of turn.

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 fights up to one target creature you don't control.

Dragon Throne of Tarkir

Equipped creature has defender and "{2}, {T}: Other creatures you control gain trample and get +X/+X until end of turn, where X is this creature's power."
Equip {3}

Spark Double

You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Greater Good

Sacrifice a creature: Draw cards equal to the sacrificed creature's power, then discard three cards.

Vivid Grove

This land enters tapped with two charge counters on it.
{T}: Add {G}.
{T}, Remove a charge counter from this land: Add one mana of any color.

Brawn

Trample
As long as this card is in your graveyard and you control a Forest, creatures you control have trample.

Rampant Growth

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

Death Wind

Target creature gets -X/-X until end of turn.

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Hungering Hydra

This creature enters with X +1/+1 counters on it.
This creature can't be blocked by more than one creature.
Whenever this creature is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Keeper of Fables

Whenever one or more non-Human creatures you control deal combat damage to a player, draw a card.

Villainous Wealth

Target opponent exiles the top X cards of their library. You may cast any number of spells with mana value X or less from among them without paying their mana costs.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

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.

Castle Garenbrig

This land enters tapped unless you control a Forest.
{T}: Add {G}.
{2}{G}{G}, {T}: Add six {G}. Spend this mana only to cast creature spells or activate abilities of creatures.

Golgari Rot Farm

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Forest

Swamp

Dimir Signet

Fauna Shaman

{G}, {T}, Discard a creature card: Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land you control enters, you gain 1 life.

Evolutionary Leap

{G}, Sacrifice a creature: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.

Freed from the Real

Enchant creature
{U}: Tap enchanted creature.
{U}: Untap enchanted creature.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Steelbane Hydra

This creature enters with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from this creature: Destroy target artifact or enchantment.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Protean Hydra

This creature enters with X +1/+1 counters on it.
If damage would be dealt to this creature, prevent that damage and remove that many +1/+1 counters from it.
Whenever a +1/+1 counter is removed from this creature, put two +1/+1 counters on it at the beginning of the next end step.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
This creature 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.

Gaze of Granite

Destroy each nonland permanent with mana value X or less.

Darkwater Catacombs

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Wood Elves

When this creature enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.