Genesis Hydra

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.
This creature enters with X +1/+1 counters on it.

Island

Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Underground Sea

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Primordial Hydra

This creature enters with X +1/+1 counters on it.
At the beginning of your upkeep, double the number of +1/+1 counters on this creature.
This creature has trample as long as it has ten or more +1/+1 counters on it.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Stonecoil Serpent

Reach, trample, protection from multicolored
This creature enters with X +1/+1 counters on it.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Concordant Crossroads

Kruphix, God of Horizons

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.

Heroic Intervention

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

Hooded Hydra

This creature enters with X +1/+1 counters on it.
When this creature dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As this creature is turned face up, put five +1/+1 counters on it.

Swamp

Tropical Island

Simic Ascendancy

{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 this enchantment.
At the beginning of your upkeep, if this enchantment has twenty or more growth counters on it, you win the game.

Farseek

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

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Gargos, Vicious Watcher

Vigilance
Hydra spells you cast cost {4} less to cast.
Whenever a creature you control becomes the target of a spell, Gargos fights up to one target creature you don't control.

Erebos's Intervention

Choose one —
• Target creature gets -X/-X until end of turn. You gain X life.
• Exile up to twice X target cards from graveyards.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Exotic Orchard

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

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Bayou

Zagoth Crystal

{T}: Add {B}, {G}, or {U}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Verdant Catacombs

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Zaxara, the Exemplary

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.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Mistcutter Hydra

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

Corpsejack Menace

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.

Forest

Sol Ring

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Arcane Signet

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Selvala, Heart of the Wilds

Whenever another creature enters, 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.

Polluted Delta

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

Elemental Bond

Whenever a creature you control with power 3 or greater enters, draw a card.

Choking Vines

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.)

Birds of Paradise

Vastwood Hydra

This creature enters with X +1/+1 counters on it.
When this creature dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on this creature among any number of creatures you control.

Mind Spring

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Misty Rainforest

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

Gang Up

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.)
Destroy target creature with power X or less.

Rampant Growth

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

Torment of Hailfire

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

Hungering Hydra

This creature enters with X +1/+1 counters on it.
This creature can't be blocked by more than one creature.
Whenever this creature is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Carpet of Flowers

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

Reyhan, Last of the Abzan

Reyhan enters with three +1/+1 counters on it.
Whenever a creature you control dies or is put into the command zone, if it had one or more +1/+1 counters on it, you may put that many +1/+1 counters on target creature.
Partner (You can have two commanders if both have partner.)

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Command Tower

Finale of Devastation

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

Lifeblood Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature dies, you gain life and draw cards equal to its power.

Braingeyser

Doubling Season

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.

Vorel of the Hull Clade

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Ertai's Meddling

X can't be 0.
Target spell's controller exiles it with X delay counters on it.
At the beginning of each of that player's upkeeps, if that card is exiled, remove a delay counter from it. If the card has no delay counters on it, the player puts it onto the stack as a copy of the original spell.

Animist's Awakening

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.

Herald's Horn

As this artifact enters, 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.

Watery Grave

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

Condescend

Counter target spell unless its controller pays {X}. Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Hydroid Krasis

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

Nyxbloom Ancient

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

Reliquary Tower

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

Overgrown Tomb

({T}: Add {B} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Displacement Wave

Return all nonland permanents with mana value X or less to their owners' hands.

Kalonian Hydra

Trample
This creature enters with four +1/+1 counters on it.
Whenever this creature attacks, double the number of +1/+1 counters on each creature you control.

Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath gets +1/+1 for each unspent green mana you have.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Green Sun's Zenith

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

Caged Sun

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Unbound Flourishing

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.

Kodama's Reach

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.