Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on this creature.

Geode Golem

Trample
Whenever this creature deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

Hardy Outlander

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, another target creature you control gets +X/+X until end of turn, where X is this creature's power."

Mountain

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Fangs of Kalonia

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on each creature that had a +1/+1 counter put on it this way.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Jodah, the Unifier

Legendary creatures you control get +X/+X, where X is the number of legendary creatures you control.
Whenever you cast a legendary spell from your hand, exile cards from the top of your library until you exile a legendary nonland card with lesser mana value. You may cast that card without paying its mana cost. Put the rest on the bottom of your library in a random order.

Forest

Jodah, Archmage Eternal

Flying
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Prevent all combat damage that would be dealt this turn.

Savageborn Hydra

Double strike
This creature enters with X +1/+1 counters on it.
{1}{R/G}: Put a +1/+1 counter on this creature. Activate only as a sorcery.

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, create X X/X green Hydra creature tokens.

Plasm Capture

Counter target spell. At the beginning of your next first main phase, add X mana in any combination of colors, where X is that spell's mana value.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Arcane Signet

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

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Sandsteppe Citadel

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

Sterling Grove

Other enchantments you control have shroud. (They can't be the targets of spells or abilities.)
{1}, Sacrifice this enchantment: Search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Command Tower

Repulsive Mutation

Put X +1/+1 counters on target creature you control. Then counter up to one target spell unless its controller pays mana equal to the greatest power among creatures you control.

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.

Sol Ring

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Plains

Cultivate

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.

Explosive Vegetation

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

Invigorating Surge

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

Brushland

{T}: Add {C}.
{T}: Add {G} or {W}. This land deals 1 damage to you.

Hydra Omnivore

Whenever this creature deals combat damage to an opponent, it deals that much damage to each other opponent.

Progenitus

Protection from everything
If Progenitus would be put into a graveyard from anywhere, reveal Progenitus and shuffle it into its owner's library instead.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Jungle Shrine

This land enters tapped.
{T}: Add {R}, {G}, or {W}.

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Traverse the Outlands

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.

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.

Swamp

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Grakmaw, Skyclave Ravager

Grakmaw enters 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.

Leyline of Mutation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

Urban Evolution

Draw three cards. You may play an additional land this turn.

Growth Spiral

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

Migration Path

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
Cycling {2} ({2}, Discard this card: Draw a card.)

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Planar Genesis

Look at the top four cards of your library. You may put a land card from among them onto the battlefield tapped. If you don't, put a card from among them into your hand. Put the rest on the bottom of your library in a random order.

Apocalypse Hydra

This creature enters with X +1/+1 counters on it. If X is 5 or more, it enters with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from this creature: It deals 1 damage to any target.

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

The Goose Mother

Flying
The Goose Mother enters with X +1/+1 counters on it.
When The Goose Mother enters, create half X Food tokens, rounded up.
Whenever The Goose Mother attacks, you may sacrifice a Food. If you do, draw a card.

Frontier Bivouac

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

Seaside Citadel

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

Generous Gift

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

Rampant Growth

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

Farseek

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

Counterspell

Villainous Wealth

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.

Savage Lands

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

Island

Kodama's Reach

Tavern Brawler

Commander creatures you own have "At the beginning of your upkeep, exile the top card of your library. This creature gets +X/+0 until end of turn, where X is that card's mana value. You may play that card this turn."

Finest Hour

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, if it's the first combat phase of the turn, untap that creature. After this phase, there is an additional combat phase.

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.

Phytohydra

If damage would be dealt to this creature, put that many +1/+1 counters on it instead.

Visions of Dominance

Put a +1/+1 counter on target creature, then double the number of +1/+1 counters on it.
Flashback {8}{G}{G}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Shivan Devastator

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

Opulent Palace

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

Goldvein Hydra

Vigilance, trample, haste
This creature enters with X +1/+1 counters on it.
When this creature dies, create a number of tapped Treasure tokens equal to its power.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Cinder Glade

({T}: Add {R} or {G}.)
This land enters tapped unless you control two or more basic lands.

Circuitous Route

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.

Inspiring Call

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.)

Zur the Enchanter

Flying
Whenever Zur attacks, you may search your library for an enchantment card with mana value 3 or less, put it onto the battlefield, then shuffle.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. This land deals 1 damage to you.

Skyshroud Claim

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

Beast Within

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

Agent of the Shadow Thieves

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

Rickety Gazebo

When you unlock this door, mill four cards, then return up to two permanent cards from among them to your hand.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Greenhouse

Lands you control have "{T}: Add one mana of any color."
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Greenhouse // Rickety Gazebo

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.

Explore

You may play an additional land this turn.
Draw a card.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.