At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

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

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

Draw a card. You may put a land card from your hand onto the battlefield.

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

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

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.

Draw X cards.

At the beginning of your upkeep, draw a card if you control a creature with the greatest power among creatures on the battlefield. Otherwise, put a +1/+1 counter on a creature you control.

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.

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.

{1}{G}{U}: Put a +1/+1 counter on target creature you control. Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy. At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

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

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.

Counter target spell.

Creatures you control have hexproof. {1}{G}: Regenerate target creature. (The next time it would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

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

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.)

If a creature would deal combat damage to Ironscale Hydra, prevent that damage and put a +1/+1 counter on Ironscale Hydra.

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.

Put a +1/+1 counter on each of up to X target creatures you control. Auras, Equipment, and modified creatures you control gain hexproof until end of turn. (Equipment, Auras you control, and counters are modifications.)

Return X target creature cards from your graveyard to your hand.

{T}: Add {C}. {G}{U}, {T}: You may cast spells this turn as though they had flash.

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

{T}: Add {G}. Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

({T}: Add {G} or {U}.) As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

Deathcap Glade enters the battlefield tapped unless you control two or more other lands. {T}: Add {B} or {G}.

Dreamroot Cascade enters the battlefield tapped unless you control two or more other lands. {T}: Add {G} or {U}.

{T}: Add one mana of any color that a land an opponent controls could produce.

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

{T}: Add {C}. {G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

({T}: Add {G}.)

({T}: Add {U}.)

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

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

({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.

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.)

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

You have no maximum hand size. {T}: Add {C}.

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

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands. {T}: Add {U} or {B}.

({T}: Add {B}.)

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

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

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

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

({T}: Add {U} or {B}.) As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

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.

You have no maximum hand size. {T}: Add one mana of any color.

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

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

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.

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

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

Search your library for a Forest card, put it onto the battlefield, then shuffle.

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

Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.

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

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Enchant creature, land, or planeswalker Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Destroy up to X target artifacts and/or enchantments. Create twice X 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life."

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Enchant permanent Enchanted permanent is a colorless Forest land.

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.

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

Destroy target nonland permanent and all other permanents with the same name as that permanent.

{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.

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

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}.)

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.

Creatures you control have base power and toughness X/X until end of turn.

Capricopian enters the battlefield with X +1/+1 counters on it. {2}: Put a +1/+1 counter on Capricopian, then you may reselect which player Capricopian is attacking. Only the player Capricopian is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

Casualty 3 (As you cast this spell, you may sacrifice a creature with power 3 or greater. When you do, copy this spell.) You draw X cards and you lose X life.

{X}{G}{G}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.) As long as Domesticated Hydra is monstrous, it has trample.

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

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.

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.

Hooded Hydra enters the battlefield 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.

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

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.

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.

Flying Nimbus Swimmer enters the battlefield with X +1/+1 counters on it.

Flying Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

When Oubliette enters the battlefield, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

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.

Changeling (This card is every creature type.) As Realmwalker enters the battlefield, choose a creature type. You may look at the top card of your library any time. You may cast creature spells of the chosen type from the top of your library.

When The Meathook Massacre enters the battlefield, 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.

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

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 of your library in a random order. Multiple instances of cascade each trigger separately.)

Trample Bioessence Hydra enters the battlefield with a +1/+1 counter on it for each loyalty counter on planeswalkers you control. Whenever one or more loyalty counters are put on planeswalkers you control, put that many +1/+1 counters on Bioessence Hydra.

{2}, {T}: Add {B} for each Swamp you control.

Clockwork Hydra enters the battlefield with four +1/+1 counters on it. Whenever Clockwork Hydra attacks or blocks, remove a +1/+1 counter from it. If you do, Clockwork Hydra deals 1 damage to any target. {T}: Put a +1/+1 counter on Clockwork Hydra.

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

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.

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

Destroy target creature. You lose 2 life.

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

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

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.

Choose one — • Destroy target artifact. • Destroy target enchantment. • Exile target card from a graveyard.

{T}: Add {C}. {U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Each land is a Swamp in addition to its other land types.

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.