Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

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 an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

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.

Genomic Enhancement -- {T}: Add one mana of any color. If this mana is spent to cast a creature spell, that creature enters the battlefield with an additional +1/+1 counter on it.

Bojuka Bog enters the battlefield tapped.

When Bojuka Bog enters the battlefield, exile target player's graveyard.

{T}: Add {B}.

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.

Trample

Domain -- Whenever Briar Hydra deals combat damage to a player, put X +1/+1 counters on target creature you control, where X is the number of basic land types among lands you control.

Target creature you control deals damage equal to its power to each other creature and each opponent.

Proclamator Hailer -- Each creature you control gets +1/+1 for each +1/+1 counter on it.

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

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.

{T}: Add {R}.

{T}: Add {G}.

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.

Cut deals 4 damage to target creature.

---

Aftermath (Cast this spell only from your graveyard. Then exile it.)

Each opponent loses X life.

{T}: Add {B}.

{T}: Add {G}.

Desert of the Indomitable enters the battlefield tapped.

{T}: Add {G}.

Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)

Creatures you control get +1/+0.

+1: Add {R} or {G}. Creature spells you cast this turn can't be countered.

-2: Target creature you control fights target creature you don't control.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Green spells you cast cost {1} less to cast.

Each opponent loses X life. You gain life equal to the life lost this way.

{T}: Add {C}.

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

({T}: Add {G}.)

({T}: Add {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 Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.

Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)

Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

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.

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

Grakmaw, Skyclave Ravager enters the battlefield with three +1/+1 counters on it.

Whenever another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on Grakmaw.

When Grakmaw dies, create an X/X black and green Hydra creature token, where X is the number of +1/+1 counters on Grakmaw.

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

Gyrus, Waker of Corpses enters the battlefield with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.

Whenever Gyrus attacks, you may exile target creature card with lesser power from your graveyard. If you do, create a token that's a copy of that card and that's tapped and attacking. Exile the token at end of combat.

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.

{T}: Add {C}.

{T}, Pay 1 life: Add {G}.

{1}{G}{G}, {T}, Sacrifice a Desert: Target creature gets +3/+3 until end of turn. Activate only as a sorcery.

Heroes' Bane enters the battlefield with four +1/+1 counters on it.

{2}{G}{G}: Put X +1/+1 counters on Heroes' Bane, where X is its power.

Permanents you control gain hexproof and indestructible until end of turn.

Trample

Embalm {3}{G} ({3}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Snake Hydra with no mana cost. Embalm only as a sorcery.)

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

Hungering Hydra can't be blocked by more than one creature.

Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

{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.

{T}: Add {C}.

{T}, Pay 1 life: Add {B}.

{2}{B}{B}, {T}, Sacrifice a Desert: Put two -1/-1 counters on target creature an opponent controls. Activate only as a sorcery.

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}.

{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

{T}: Add {C}.

{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

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.

If you control two or more other lands, Lair of the Hydra enters the battlefield tapped.

{T}: Add {G}.

{X}{G}: Until end of turn, Lair of the Hydra becomes an X/X green Hydra creature. It's still a land. X can't be 0.

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.

{T}, Pay 1 life: Add one mana of any color.

Trample

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

This spell can't be countered.

Haste, protection from blue

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

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

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)

Mosswort Bridge enters the battlefield tapped.

{T}: Add {G}.

{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

({T}: Add {R}.)

({T}: Add {R}.)

As Neverwinter Hydra enters the battlefield, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.

Trample

Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)

{T}: Add {C}.

{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Trample

Landfall -- Whenever a land enters the battlefield under your control, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

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

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

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

{1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery.

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

Path of Ancestry enters the battlefield tapped.

{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Polukranos enters the battlefield 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.

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

When Polukranos, World Eater becomes monstrous, it deals X damage divided as you choose among any number of target creatures your opponents control. Each of those creatures deals damage equal to its power to Polukranos.

If one or more tokens would be created, twice that many of those tokens are created instead.

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

Rampant Rejuvenator enters the battlefield with two +1/+1 counters on it.

When Rampant Rejuvenator dies, search your library for up to X basic land cards, where X is Rampant Rejuvenator's power, put them onto the battlefield, then shuffle.

Vigilance, reach, trample

Ramunap Hydra gets +1/+1 as long as you control a Desert.

Ramunap Hydra gets +1/+1 as long as there is a Desert card in your graveyard.

You have no maximum hand size.

{T}: Add {C}.

Green creature spells you cast cost {1} less to cast.

Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.

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.

When Riveteers Overlook enters the battlefield, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

{T}: Add {C}.

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

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

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

Whenever you cast a creature spell with mana value 5 or greater, that creature enters the battlefield with X additional +1/+1 counters on it, where X is its mana value minus 4.

Creatures you control with three or more +1/+1 counters on them have haste.

{T}: Add {G}.

Savage Lands enters the battlefield tapped.

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

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.

{T}: Add {C}.

{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Whenever another creature enters the battlefield, its controller may draw a card if its power is greater than each other creature's power.

{G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

Flying, haste

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

Strive -- This spell costs {1}{G} more to cast for each target beyond the first.

Choose any number of target creatures. Double the number of +1/+1 counters on each of them.

{T}: Add three mana of any one color. Spend this mana only to cast creature spells.

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 {B}.)

({T}: Add {B}.)

This spell costs {X} less to cast, where X is the greatest power among creatures you control.

{T}: Add {G}{G}. You gain 2 life.

Whenever a nontoken creature enters the battlefield under your control, put a +1/+1 counter on it and draw a card.

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

{T}: Add {C}.

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

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.

As Urza's Incubator enters the battlefield, choose a creature type.

Creature spells of the chosen type cost {2} less to cast.

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

Trample

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

When Voracious Hydra enters the battlefield, choose one --

• Double the number of +1/+1 counters on Voracious Hydra.

• Voracious Hydra fights target creature you don't control.

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.

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.

If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.

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

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest.

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

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.

{T}: Add {C}.

{G}, {T}: Regenerate target creature.

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

Ziatora's Proving Ground enters the battlefield tapped.

Cycling {3} ({3}, Discard this card: Draw a card.)