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.

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.

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.

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.)

Enchant creature When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature. At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on that creature.

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

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.

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

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.

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.

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.

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

{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.

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.

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.

Whenever you cast a creature spell, draw a card.

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.

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.

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.

At the beginning of your upkeep, scry 1. Whenever you cast a creature spell, you may pay {G}. If you do, draw a card.

Prime Speaker Zegana enters the battlefield with X +1/+1 counters on it, where X is the greatest power among other creatures you control. When Prime Speaker Zegana enters the battlefield, draw cards equal to its power.

Creatures you control have haste. Whenever a creature with power 4 or greater enters the battlefield under your control, you may draw a card.

Creatures you control with +1/+1 counters on them can't be blocked.

{T}: Add {C}. {3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

({T}: Add {R} or {G}.) Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

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

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

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

({T}: Add {G}.)

Frontier Bivouac enters the battlefield tapped. {T}: Add {G}, {U}, or {R}.

Gruul Turf enters the battlefield tapped. When Gruul Turf enters the battlefield, return a land you control to its owner's hand. {T}: Add {R}{G}.

({T}: Add {U}.)

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

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.

({T}: Add {R}.)

{T}: Add {C}. {1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents. {T}: Add {G} or {U}.

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

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

Rugged Highlands enters the battlefield tapped. When Rugged Highlands enters the battlefield, you gain 1 life. {T}: Add {R} or {G}.

Simic Growth Chamber enters the battlefield tapped. When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand. {T}: Add {G}{U}.

Swiftwater Cliffs enters the battlefield tapped. When Swiftwater Cliffs enters the battlefield, you gain 1 life. {T}: Add {U} or {R}.

Temple of Mystery enters the battlefield tapped. When Temple of Mystery enters the battlefield, scry 1. {T}: Add {G} or {U}.

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

When Deepglow Skate enters the battlefield, double the number of each kind of counter on any number of target permanents.

Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield. You may cast spells as though they had flash.

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

Reveal the top X cards of your library. Put all land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order. Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap those lands.

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

Search your library for up to X basic land cards, where X is the number of lands you control, put them onto the battlefield tapped, then shuffle.

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.

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

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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

Spells cost {1} less to cast.

As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Whenever you tap a Forest for mana, add an additional {G}. +1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land. −8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle.

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.

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

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

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

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

{3}, {T}: Create a colorless snow artifact token named Icy Manalith with "{T}: Add one mana of any color." {6}{R}{G}, {T}: Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

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

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

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.

Counter target spell.

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.

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.

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.