Prevent all combat damage that would be dealt this turn.

Hydroid Krasis

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.

Murkfiend Liege

Other green creatures you control get +1/+1.
Other blue creatures you control get +1/+1.
Untap all green and/or blue creatures you control during each other player's untap step.

Peel from Reality

Return target creature you control and target creature you don't control to their owners' hands.

Island

Reclamation Sage

When Reclamation Sage enters the battlefield, you may destroy target artifact or enchantment.

Dissipate

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Counterspell

Sporemound

Landfall — Whenever a land enters the battlefield under your control, create a 1/1 green Saproling creature token.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Simic Guildgate

Simic Guildgate enters the battlefield tapped.
{T}: Add {G} or {U}.

Mulldrifter

Flying
When Mulldrifter enters the battlefield, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Fog Bank

Defender, flying
Prevent all combat damage that would be dealt to and dealt by Fog Bank.

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.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Pursued Whale

When Pursued Whale enters the battlefield, each opponent creates a 1/1 red Pirate creature token with "This creature can't block" and "Creatures you control attack each combat if able."
Spells your opponents cast that target Pursued Whale cost {3} more to cast.

Hall of Oracles

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.

Vivid Grove

Vivid Grove enters the battlefield tapped with two charge counters on it.
{T}: Add {G}.
{T}, Remove a charge counter from Vivid Grove: Add one mana of any color.

Primeval Bounty

Whenever you cast a creature spell, create a 3/3 green Beast creature token.
Whenever you cast a noncreature spell, put three +1/+1 counters on target creature you control.
Landfall — Whenever a land enters the battlefield under your control, you gain 3 life.

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 Shipbreaker Kraken becomes monstrous, tap up to four target creatures. Those creatures don't untap during their controllers' untap steps for as long as you control Shipbreaker Kraken.

Growth Spiral

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

Sphinx of Uthuun

Flying
When Sphinx of Uthuun enters the battlefield, reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Thornwood Falls

Thornwood Falls enters the battlefield tapped.
When Thornwood Falls enters the battlefield, you gain 1 life.
{T}: Add {G} or {U}.

Simic Sky Swallower

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

Terastodon

When Terastodon enters the battlefield, you may destroy up to three target noncreature permanents. For each permanent put into a graveyard this way, its controller creates a 3/3 green Elephant creature token.

Ramunap Excavator

Thought Vessel

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

Lotus Cobra

Landfall — Whenever a land enters the battlefield under your control, add one mana of any color.

Verdant Sun's Avatar

Whenever Verdant Sun's Avatar or another creature enters the battlefield under your control, you gain life equal to that creature's toughness.

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

Rampaging Baloths

Trample
Landfall — Whenever a land enters the battlefield under your control, you may create a 4/4 green Beast creature token.

Arixmethes, Slumbering Isle

Arixmethes, Slumbering Isle enters the battlefield 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}.

Whelming Wave

Return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.

Cultivate

Trench Behemoth

Return a land you control to its owner's hand: Untap Trench Behemoth. It gains hexproof until end of turn.
Landfall — Whenever a land enters the battlefield under your control, target creature an opponent controls attacks during its controller's next combat phase if able.

Yavimaya Elder

When Yavimaya Elder dies, you may search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
{2}, Sacrifice Yavimaya Elder: Draw a card.

Stumpsquall Hydra

When Stumpsquall Hydra enters the battlefield, distribute X +1/+1 counters among it and any number of commanders.

Beast Within

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

Garruk's Uprising

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)
Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Court of Bounty

When Court of Bounty enters the battlefield, you become the monarch.
At the beginning of your upkeep, you may put a land card from your hand onto the battlefield. If you're the monarch, instead you may put a creature or land card from your hand onto the battlefield.

Scourge of Fleets

When Scourge of Fleets enters the battlefield, 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.

Eternal Witness

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Nemesis of Reason

Whenever Nemesis of Reason attacks, defending player mills ten cards.

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 Charm

Choose one —
• Target creature gets +3/+3 until end of turn.
• Permanents you control gain hexproof until end of turn.
• Return target creature to its owner's hand.

Molimo, Maro-Sorcerer

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Molimo, Maro-Sorcerer's power and toughness are each equal to the number of lands you control.

Memorial to Genius

Memorial to Genius enters the battlefield tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Slinn Voda, the Rising Deep

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
When Slinn Voda, the Rising Deep enters the battlefield, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Aesi, Tyrant of Gyre Strait

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

Divination

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.

Simic Growth Chamber

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}.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Guard Gomazoa

Defender, flying
Prevent all combat damage that would be dealt to Guard Gomazoa.

Sol Ring

Convolute

Counter target spell unless its controller pays {4}.

Forest

Retreat to Kazandu

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Put a +1/+1 counter on target creature.
• You gain 2 life.

Wickerbough Elder

Wickerbough Elder enters the battlefield with a -1/-1 counter on it.
{G}, Remove a -1/-1 counter from Wickerbough Elder: Destroy target artifact or enchantment.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Oran-Rief Hydra

Trample
Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

Avenger of Zendikar

When Avenger of Zendikar enters the battlefield, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land enters the battlefield under your control, you may put a +1/+1 counter on each Plant creature you control.

Coral Atoll

Coral Atoll enters the battlefield tapped.
When Coral Atoll enters the battlefield, sacrifice it unless you return an untapped Island you control to its owner's hand.
{T}: Add {C}{U}.

Turn Aside

Counter target spell that targets a permanent you control.

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Woodland Stream

Woodland Stream enters the battlefield tapped.
{T}: Add {G} or {U}.

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Into the Roil

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Reliquary Tower

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters the battlefield, destroy target artifact, enchantment, or land.

Mana Leak

Counter target spell unless its controller pays {3}.

Spitting Image

Create a token that's a copy of target creature.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Koma, Cosmos Serpent

This spell can't be countered.
At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil.
Sacrifice another Serpent: Choose one —
• Tap target permanent. Its activated abilities can't be activated this turn.
• Koma, Cosmos Serpent gains indestructible until end of turn.

Command Tower

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

Meloku the Clouded Mirror

Flying
{1}, Return a land you control to its owner's hand: Create a 1/1 blue Illusion creature token with flying.