This spell can't be countered.

You may have Altered Ego enter the battlefield as a copy of any creature on the battlefield, except it enters with X additional +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.

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.

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.)

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)

Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

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

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

Sacrifice Commander's Sphere: Draw a card.

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.

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.

Other Elf creatures you control get +1/+1.

{T}: Add {G} for each Elf you control.

{T}: Add {G}.

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

Surge {X}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)

Fall of the Titans deals X damage to each of up to two targets.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

Populate X times. (To populate, create a token that's a copy of a creature token you control. Do this X times.)

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.

Gateway Plaza enters the battlefield tapped.

When Gateway Plaza enters the battlefield, sacrifice it unless you pay {1}.

{T}: Add one mana of any color.

Create X X/X green Ooze creature tokens.

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}.

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

{T}: Add {G} for each +1/+1 counter on Gyre Sage.

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.

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

{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

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.

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.

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.

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.)

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

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

Level up {1}{G} ({1}{G}: Put a level counter on this. Level up only as a sorcery.)

LEVEL 1-4

1/2

{T}: Add {G}{G}.

LEVEL 5+

1/4

Elves you control have "{T}: Add {G}{G}."

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 an amount of {G} equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

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.

Indestructible

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

You have no maximum hand size.

If you would lose unspent mana, that mana becomes colorless instead.

{T}: Add {C} for each card you've drawn this turn.

Partner (You can have two commanders if both have partner.)

Lavalanche deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

{T}: Add {G}.

{T}: Add {C}.

{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Trample

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

Draw X cards.

This spell can't be countered.

Haste, protection from blue

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

({T}: Add {R}.)

({T}: Add {R}.)

({T}: Add {R}.)

+2: Scry 2.

0: Look at the top card of your library. If it's a land card or a creature card with mana value less than or equal to the number of loyalty counters on Nissa, Steward of Elements, you may put that card onto the battlefield.

-6: Untap up to two target lands you control. They become 5/5 Elemental creatures with flying and haste until end of turn. They're still lands.

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.

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.

Orochi Hatchery enters the battlefield with X charge counters on it.

{5}, {T}: Create a 1/1 green Snake creature token for each charge counter on Orochi Hatchery.

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.

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.

Choose two --

• Target player loses X life.

• Return target creature card with mana value X or less from your graveyard to the battlefield.

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

• Up to X target creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)

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.

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

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

{T}: Add {C}{C}{C}{C}. Spend this mana only on costs that contain {X}.

Rupture Spire enters the battlefield tapped.

When Rupture Spire enters the battlefield, sacrifice it unless you pay {1}.

{T}: Add one mana of any color.

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.

Reach

{X}{G}{G}: Silklash Spider deals X damage to each creature with flying.

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}.

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

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.

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)

Choose target creature, then choose another target creature for each time this spell was kicked. Put X +1/+1 counters on each of them.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

Temple of Abandon enters the battlefield tapped.

When Temple of Abandon enters the battlefield, scry 1.

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

{T}: Add {C}{C}. Activate only if you control five or more lands.

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

Whenever you cast a spell with mana value 5 or greater, draw a card.

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.

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

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 your first spell each turn, choose an opponent at random. Vial Smasher the Fierce deals damage equal to that spell's mana value to that player or a planeswalker that player controls.

Partner (You can have two commanders if both have partner.)

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.

Wildwood Scourge enters the battlefield with X +1/+1 counters on it.

Whenever one or more +1/+1 counters are put on another non-Hydra creature you control, put a +1/+1 counter on Wildwood Scourge.

+1: Add X mana in any combination of {R} and/or {G}, where X is the number of creatures you control.

0: Create a 2/2 red and green Satyr creature token with haste.

-6: Exile the top seven cards of your library. You may put any number of creature and/or land cards from among them onto the battlefield.

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.