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.

Fork in the Road

Search your library for up to two basic land cards and reveal them. Put one into your hand and the other into your graveyard. Then shuffle.

Inkwell Leviathan

Trample
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Shroud (This creature can't be the target of spells or abilities.)

Nimbus Swimmer

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

Dreamroot Cascade

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

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.

Harvest Season

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

Circle of Dreams Druid

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

Clear the Mind

Target player shuffles their graveyard into their library.
Draw a card.

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.

Arixmethes, Slumbering Isle

Arixmethes enters tapped with five slumber counters on it.
As long as Arixmethes has a slumber counter on it, it's a land. (It's not a creature.)
Whenever you cast a spell, you may remove a slumber counter from Arixmethes.
{T}: Add {G}{U}.

Kraken Hatchling

Shipbreaker Kraken

{6}{U}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, tap up to four target creatures. Those creatures don't untap during their controllers' untap steps for as long as you control this creature.

Beneath the Sands

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

Breaching Leviathan

When this creature enters, if you cast it from your hand, tap all nonblue creatures. Those creatures don't untap during their controllers' next untap steps.

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.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Beastcaller Savant

Haste
{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Brinelin, the Moon Kraken

When Brinelin enters and whenever you cast a spell with mana value 6 or greater, you may return target nonland permanent to its owner's hand.
Partner (You can have two commanders if both have partner.)

Gond Gate

Gates you control enter untapped.
{T}: Add {C}.
{T}: Add one mana of any color that a Gate you control could produce.

Desert of the Indomitable

This land enters tapped.
{T}: Add {G}.
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Breakthrough

Draw four cards, then choose X cards in your hand and discard the rest.

Farseek

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

Balance of Power

If target opponent has more cards in hand than you, draw cards equal to the difference.

Scourge of Fleets

When this creature enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Domesticated Hydra

{X}{G}{G}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
As long as this creature is monstrous, it has trample.

Simic Guildgate

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

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Island

Trench Gorger

Trample
When this creature enters, you may search your library for any number of land cards, exile them, then shuffle. If you do, this creature has base power and base toughness each equal to the number of cards exiled this way.

Stormsurge Kraken

Hexproof
Lieutenant — As long as you control your commander, this creature gets +2/+2 and has "Whenever this creature becomes blocked, you may draw two cards."

Gateway Plaza

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Desert of the Mindful

This land enters tapped.
{T}: Add {U}.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

Bioessence Hydra

Trample
This creature enters with a +1/+1 counter on it for each loyalty counter on planeswalkers you control.
Whenever one or more loyalty counters are put on planeswalkers you control, put that many +1/+1 counters on this creature.

Crashing Tide

This spell has flash as long as you control a Merfolk.
Return target creature to its owner's hand.
Draw a card.

Command Tower

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

Khalni Heart Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on this enchantment.
Remove three quest counters from this enchantment and sacrifice it: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Ironscale Hydra

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

Coral Atoll

This land enters tapped.
When this land enters, sacrifice it unless you return an untapped Island you control to its owner's hand.
{T}: Add {C}{U}.

Far Wanderings

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
Threshold — If seven or more cards are in your graveyard, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

Stormtide Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
All lands are Islands in addition to their other types.
Creatures without flying or islandwalk can't attack.

Explosive Vegetation

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

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Spawning Kraken

Whenever a Kraken, Leviathan, Octopus, or Serpent you control deals combat damage to a player, create a 9/9 blue Kraken creature token.

Devastation Tide

Return all nonland permanents to their owners' hands.
Miracle {1}{U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Kiora, the Crashing Wave

+1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.
−1: Draw a card. You may play an additional land this turn.
−5: You get an emblem with "At the beginning of your end step, create a 9/9 blue Kraken creature token."

Kederekt Leviathan

When this creature enters, return all other nonland permanents to their owners' hands.
Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Celebrate the Harvest

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

Tishana, Voice of Thunder

Tishana's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
When Tishana enters, draw a card for each creature you control.

Winged Temple of Orazca

(Transforms from Hadana's Climb.)
{T}: Add one mana of any color.
{1}{G}{U}, {T}: Target creature you control gains flying and gets +X/+X until end of turn, where X is its power.

Hadana's Climb

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if that creature has three or more +1/+1 counters on it, transform Hadana's Climb.

Hadana's Climb // Winged Temple of Orazca

Manor Gate

This land enters tapped.
As this land enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Heroes' Bane

This creature enters with four +1/+1 counters on it.
{2}{G}{G}: Put X +1/+1 counters on this creature, where X is its power.

Feral Hydra

This creature enters with X +1/+1 counters on it.
{3}: Put a +1/+1 counter on this creature. Any player may activate this ability.

Havenwood Battleground

This land enters tapped.
{T}: Add {G}.
{T}, Sacrifice this land: Add {G}{G}.

Protean Hydra

This creature enters with X +1/+1 counters on it.
If damage would be dealt to this creature, prevent that damage and remove that many +1/+1 counters from it.
Whenever a +1/+1 counter is removed from this creature, put two +1/+1 counters on it at the beginning of the next end step.

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.

Halimar Depths

This land enters tapped.
When this land enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Lay of the Land

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Nadir Kraken

Whenever you draw a card, you may pay {1}. If you do, put a +1/+1 counter on this creature and create a 1/1 blue Tentacle creature token.

Sea Gate

This land enters tapped.
As this land enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Parallel Evolution

For each creature token on the battlefield, its controller creates a token that's a copy of that creature.
Flashback {4}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Basilisk Gate

{T}: Add {C}.
{2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Boundless Realms

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.

Kiora, Master of the Depths

+1: Untap up to one target creature and up to one target land.
−2: Reveal the top four cards of your library. You may put a creature card and/or a land card from among them into your hand. Put the rest into your graveyard.
−8: You get an emblem with "Whenever a creature you control enters, you may have it fight target creature." Then create three 8/8 blue Octopus creature tokens.

Ancient Ziggurat

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Mistcutter Hydra

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

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Collective Voyage

Join forces — Starting with you, each player may pay any amount of mana. Each player searches their library for up to X basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles.

Zegana, Utopian Speaker

When Zegana enters, if you control another creature with a +1/+1 counter on it, draw a card.
{4}{G}{U}: Adapt 4. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Deep-Sea Kraken

This creature can't be blocked.
Suspend 9—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever an opponent casts a spell, if this card is suspended, remove a time counter from it.

Kiora Bests the Sea God

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create an 8/8 blue Kraken creature token with hexproof.
II — Tap all nonland permanents target opponent controls. They don't untap during their controller's next untap step.
III — Gain control of target permanent an opponent controls. Untap it.

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Kiora's Dambreaker

When this creature enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Kraken of the Straits

Creatures with power less than the number of Islands you control can't block this creature.

Tromokratis

Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Simic Sky Swallower

Flying, trample
Shroud (This creature can't be the target of spells or abilities.)

Charix, the Raging Isle

Spells your opponents cast that target Charix cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Kiora's Dismissal

Strive — This spell costs {U} more to cast for each target beyond the first.
Return any number of target enchantments to their owners' hands.

Forest

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.

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land you control enters, you may draw a card.

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.