X

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.

Balduvian Hydra enters the battlefield with X +1/+0 counters on it.

Remove a +1/+0 counter from Balduvian Hydra: Prevent the next 1 damage that would be dealt to Balduvian Hydra this turn.

{R}{R}{R}: Put a +1/+0 counter on Balduvian Hydra. Activate this ability only during your upkeep.

Target attacking creature gets +X/+0 until end of turn.

Draw a card at the beginning of the next turn's upkeep.

Banefire deals X damage to any target.

If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Blaze deals X damage to any target.

Bonfire of the Damned deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

Miracle {X}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Cast this spell only during the declare blockers step.

X target attacking creatures become blocked. Choking Vines deals 1 damage to each of those creatures. (This spell works on creatures that can't be blocked.)

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Search your library for a creature card with converted mana cost X or less and put it onto the battlefield. Then shuffle your library.

Conflagrate deals X damage divided as you choose among any number of targets.

Flashback—{R}{R}, Discard X cards. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Crater's Claws deals X damage to any target.

Ferocious — Crater's Claws deals X plus 2 damage instead if you control a creature with power 4 or greater.

Detritivore's power and toughness are each equal to the number of nonbasic land cards in your opponents' graveyards.

Suspend X—{X}{3}{R}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{3}{R} and exile it with X time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Whenever a time counter is removed from Detritivore while it's exiled, destroy target nonbasic land.

Dwarven Catapult deals X damage divided evenly, rounded down, among all creatures target opponent controls.

Electrodominance deals X damage to any target. You may cast a spell with converted mana cost X or less from your hand without paying its mana cost.

Endless One enters the battlefield with X +1/+1 counters on it.

Target creature gets +X/+0 until end of turn.

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.

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.

Search your library and/or graveyard for a creature card with converted mana cost X or less and put it onto the battlefield. If you search your library this way, shuffle it. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with converted mana cost X or less without paying their mana costs. If a spell cast this way would be put into your graveyard this turn, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

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

Fireball deals X damage divided evenly, rounded down, among any number of targets.

Create X 1/1 red Elemental Cat creature tokens with haste. Exile them at the beginning of the next end step.

Flashback—{R}{R}, Sacrifice X Mountains. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flying

Whenever Flameblast Dragon attacks, you may pay {X}{R}. If you do, Flameblast Dragon deals X damage to any target.

Flaming Gambit deals X damage to target player or planeswalker. That player or that planeswalker's controller may choose a creature they control and have Flaming Gambit deal that damage to it instead.

Flashback {X}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fungal Behemoth's power and toughness are each equal to the number of +1/+1 counters on creatures you control.

Suspend X—{X}{G}{G}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{G}{G} and exile it with X time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Whenever a time counter is removed from Fungal Behemoth while it's exiled, you may put a +1/+1 counter on target creature.

Create X X/X green Ooze creature tokens.

Search your library for a green creature card with converted mana cost X or less, put it onto the battlefield, then shuffle your library. Shuffle Green Sun's Zenith into its owner's library.

Hangarback Walker enters the battlefield with X +1/+1 counters on it.

When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.

{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

Heat Ray deals X damage to target creature.

Heroic — Whenever you cast a spell that targets Hero of Leina Tower, you may pay {X}. If you do, put X +1/+1 counters on Hero of Leina Tower.

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.)

Ivy Elemental enters the battlefield with X +1/+1 counters on it.

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)

Jaya's Immolating Inferno deals X damage to each of up to three targets.

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)

Look at the top X cards of your library. You may put any number of land and/or legendary permanent cards with converted mana cost X or less from among them onto the battlefield. Put the rest into your graveyard.

{T}: Add {C}.

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

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

{1}{G}: Regenerate Krakilin.

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.

Put X +1/+1 counters on target artifact you control. If it isn't a creature or Vehicle, it becomes a 0/0 Construct artifact creature.

Destroy target artifact or enchantment with converted mana cost X. It can't be regenerated. You gain X life.

X target blocked creatures assign their combat damage this turn as though they weren't blocked.

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.

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

For each 1 damage that would be dealt to Rock Hydra, if it has a +1/+1 counter on it, remove a +1/+1 counter from it and prevent that 1 damage.

{R}: Prevent the next 1 damage that would be dealt to Rock Hydra this turn.

{R}{R}{R}: Put a +1/+1 counter on Rock Hydra. Activate this ability only during your upkeep.

Rock Slide deals X damage divided as you choose among any number of target attacking or blocking creatures without flying.

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

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 this ability only any time you could cast a sorcery.

Defender (This creature can't attack.)

Shifting Wall enters the battlefield with X +1/+1 counters on it.

Street Spasm deals X damage to target creature without flying you don't control.

Overload {X}{X}{R}{R} (You may cast this spell for its overload cost. If you do, change its text by replacing all instances of "target" with "each.")

Creatures of the creature type of your choice get +X/+X until end of turn.

Ugin's Conjurant enters the battlefield with X +1/+1 counters on it.

If damage would be dealt to Ugin's Conjurant while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from Ugin's Conjurant.

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

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.

Kicker {X} (You may pay an additional {X} as you cast this spell.)

Saproling creatures and other Treefolk creatures get +1/+1.

When Verdeloth the Ancient enters the battlefield, if it was kicked, create X 1/1 green Saproling creature tokens.

Walking Ballista enters the battlefield with X +1/+1 counters on it.

{4}: Put a +1/+1 counter on Walking Ballista.

Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

{X}{R}: This turn, creatures can't block unless their controller pays {X} for each blocking creature they control.

Windstorm deals X damage to each creature with flying.