Apocalypse Hydra enters the battlefield with X +1/+1 counters on it. If X is 5 or more, it enters the battlefield with an additional X +1/+1 counters on it.

{1}{R}, Remove a +1/+1 counter from Apocalypse Hydra: It deals 1 damage to any target.

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

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

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension.

As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

Benevolent Hydra enters the battlefield with X +1/+1 counters on it.

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

{T}, Remove a +1/+1 counter from Benevolent Hydra: Put a +1/+1 counter on another target creature you control.

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.

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

You may spend mana as though it were mana of any color.

{T}: Add {C}{C}{C}{C}{C}.

{5}, {T}: Draw a card for each color among permanents you control.

({T}: Add {R} or {G}.)

Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {R} or {G}.)

Commercial District enters the battlefield tapped.

When Commercial District enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Copperline Gorge enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {R} or {G}.

Whenever a creature you control dies, put X +1/+1 counters on target creature you control, where X is the power of the creature that died.

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

When Dockside Extortionist enters the battlefield, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

{3}, {T}: Double the amount of each type of unspent mana you have.

Whenever a creature with power 3 or greater enters the battlefield under your control, draw a card.

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)

Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked.

{T}: Add {C} for each charge counter on Everflowing Chalice.

Target creature you control deals damage equal to its power to another target creature.

{T}: Add {C}.

{R/G}, {T}: Add {R}{R}, {R}{G}, or {G}{G}.

({T}: Add {G}.)

({T}: Add {G}.)

As Game Trail enters the battlefield, you may reveal a Mountain or Forest card from your hand. If you don't, Game Trail enters the battlefield tapped.

{T}: Add {R} or {G}.

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.

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 the battlefield with X +1/+1 counters on it.

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

{T}: Add {C}.

{T}: Add {R} or {G}. Each opponent gains 1 life.

Gruul Guildgate enters the battlefield tapped.

{T}: Add {R} or {G}.

{1}, {T}: Add {R}{G}.

({T}: Add {R} or {G}.)

Highland Forest enters the battlefield tapped.

Choose one --

• Destroy target artifact.

• Destroy target enchantment.

• Destroy target artifact and target enchantment.

{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.

Whenever Hydra Omnivore deals combat damage to an opponent, it deals that much damage to each other opponent.

Trample

Kalonian Hydra enters the battlefield with four +1/+1 counters on it.

Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

{T}: Add {C}.

{T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

Kazandu Refuge enters the battlefield tapped.

When Kazandu Refuge enters the battlefield, you gain 1 life.

{T}: Add {R} or {G}.

This spell costs {G} less to cast for each green creature you control.

Trample

Choose one. If you control a commander as you cast this spell, you may choose both.

• Breathe Flame -- Klauth's Will deals X damage to each creature without flying.

• Smash Relics -- Destroy up to X target artifacts and/or enchantments.

As an additional cost to cast this spell, sacrifice a creature.

Draw cards equal to the sacrificed creature's power.

Trample

Lifeblood Hydra enters the battlefield with X +1/+1 counters on it.

When Lifeblood Hydra dies, you gain life and draw cards equal to its power.

If you tap a permanent for mana, it produces twice as much of that mana instead.

Mana Vault doesn't untap during your untap step.

At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.

At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.

{T}: Add {C}{C}{C}.

Trample

Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

This spell can't be countered.

Haste, protection from blue

Mistcutter Hydra enters the battlefield with X +1/+1 counters on it.

{1}{R}{R}: Put a +1/+1 counter on Molten Hydra.

{T}, Remove all +1/+1 counters from Molten Hydra: It deals damage to any target equal to the number of +1/+1 counters removed this way.

{1}, {T}: Add {R}{G}.

({T}: Add {R}.)

({T}: Add {R}.)

Mountain Valley enters the battlefield tapped.

{T}, Sacrifice Mountain Valley: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Indestructible

As long as your devotion to green is less than five, Nylea isn't a creature. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Other creatures you control have trample.

{3}{G}: Target creature gets +2/+2 until end of turn.

Trample

If you tap a permanent for mana, it produces three times as much of that mana instead.

Primordial Hydra enters the battlefield with X +1/+1 counters on it.

At the beginning of your upkeep, double the number of +1/+1 counters on Primordial Hydra.

Primordial Hydra has trample as long as it has ten or more +1/+1 counters on it.

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Protean Hydra enters the battlefield with X +1/+1 counters on it.

If damage would be dealt to Protean Hydra, prevent that damage and remove that many +1/+1 counters from it.

Whenever a +1/+1 counter is removed from Protean Hydra, put two +1/+1 counters on it at the beginning of the next end step.

Trample

Creatures you control with trample have "You may have this creature assign its combat damage as though it weren't blocked."

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

Racers' Ring enters the battlefield tapped.

{T}: Add {R} or {G}.

{2}{R}{G}, {T}, Sacrifice Racers' Ring: Draw a card.

Creatures you control have double strike.

Raging Ravine enters the battlefield tapped.

{T}: Add {R} or {G}.

{2}{R}{G}: Until end of turn, Raging Ravine becomes a 3/3 red and green Elemental creature with "Whenever this creature attacks, put a +1/+1 counter on it." It's still a land.

Restless Ridgeline enters the battlefield tapped.

{T}: Add {R} or {G}.

{2}{R}{G}: Restless Ridgeline becomes a 3/4 red and green Dinosaur creature until end of turn. It's still a land.

Whenever Restless Ridgeline attacks, another target attacking creature gets +2/+0 until end of turn. Untap that creature.

Choose one --

• Destroy target artifact.

• Destroy target enchantment.

• Exile target card from a graveyard.

Creature spells you control can't be countered.

Nontoken creatures you control have riot. (They enter the battlefield with your choice of a +1/+1 counter or haste.)

Draw cards equal to the greatest power among creatures you control.

You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Target opponent may have Risk Factor deal 4 damage to them. If that player doesn't, you draw three cards.

Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Rockfall Vale enters the battlefield tapped unless you control two or more other lands.

{T}: Add {R} or {G}.

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.

{T}: Add {R} or {G}.

Rugged Highlands enters the battlefield tapped.

When Rugged Highlands enters the battlefield, you gain 1 life.

{T}: Add {R} or {G}.

Savage Twister deals X damage to each creature.

Double strike

Savageborn Hydra enters the battlefield with X +1/+1 counters on it.

{1}{R/G}: Put a +1/+1 counter on Savageborn Hydra. Activate only as a sorcery.

Trample

Scourge of Skola Vale enters the battlefield with two +1/+1 counters on it.

{T}, Sacrifice another creature: Put a number of +1/+1 counters on Scourge of Skola Vale equal to the sacrificed creature's toughness.

({T}: Add {R} or {G}.)

Sheltered Thicket enters the battlefield tapped.

Cycling {2} ({2}, Discard this card: Draw a card.)

Flying, haste

Shivan Devastator enters the battlefield with X +1/+1 counters on it.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {R}.)

({T}: Add {R}.)

{T}: Add {C}{C}.

Spire Garden enters the battlefield tapped unless you have two or more opponents.

{T}: Add {R} or {G}.

Spitting Hydra enters the battlefield with four +1/+1 counters on it.

{1}{R}, Remove a +1/+1 counter from Spitting Hydra: It deals 1 damage to target creature.

Steelbane Hydra enters the battlefield with X +1/+1 counters on it.

{2}{G}, Remove a +1/+1 counter from Steelbane Hydra: Destroy target artifact or enchantment.

({T}: Add {R} or {G}.)

As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {R} or {G}.)

Temple of Abandon enters the battlefield tapped.

When Temple of Abandon enters the battlefield, scry 1.

{T}: Add {R} or {G}.

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.

At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

{T}: Add {C}{C}{C}.

Counter target spell. Choose 1, 2, or 3 at random. Its controller mills that many cards, then exiles cards from the top of their library until they exile a nonland card with a different name than that spell. They may cast that card without paying its mana cost. Then they put the exiled cards on the bottom of their library in a random order.

Ulasht, the Hate Seed enters the battlefield with a +1/+1 counter on it for each other red creature you control and a +1/+1 counter on it for each other green creature you control.

{1}, Remove a +1/+1 counter from Ulasht: Choose one --

• Ulasht deals 1 damage to target creature.

• Create a 1/1 green Saproling creature token.

Reach

Ulvenwald Hydra's power and toughness are each equal to the number of lands you control.

When Ulvenwald Hydra enters the battlefield, you may search your library for a land card, put it onto the battlefield tapped, then shuffle.

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.

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Landfall -- Whenever a land enters the battlefield under your control, exile the top card of your library. You may play that card for as long as it remains exiled.

At the beginning of your end step, if there are cards exiled with Valakut Exploration, put them into their owner's graveyard, then Valakut Exploration deals that much damage to each opponent.

Vastwood Hydra enters the battlefield 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.

Whenever a creature enters the battlefield under your control, it deals damage equal to its power to any target.

Reach

When Whiptongue Hydra enters the battlefield, destroy all creatures with flying. Put a +1/+1 counter on Whiptongue Hydra for each creature destroyed this way.

Destroy target permanent an opponent controls. Its controller reveals cards from the top of their library until they reveal a permanent card that shares a card type with that permanent. They put that card onto the battlefield and the rest on the bottom of their library in a random order.

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

({T}: Add {R} or {G}.)

Wooded Ridgeline enters the battlefield tapped.

Indestructible

As long as your devotion to red and green is less than seven, Xenagos isn't a creature.

At the beginning of combat on your turn, another target creature you control gains haste and gets +X/+X until end of turn, where X is that creature's power.

Whenever you tap a land for mana, add one mana of any type that land produced. (The types of mana are white, blue, black, red, green, and colorless.)

Whenever you cast a creature spell, draw a card.