Negate

Wildwood Scourge

This creature enters with X +1/+1 counters on it.
Whenever one or more +1/+1 counters are put on another non-Hydra creature you control, put a +1/+1 counter on this creature.

Lore Weaver

Partner with Ley Weaver (When this creature enters, target player may put Ley Weaver into their hand from their library, then shuffle.)
{5}{U}{U}: Target player draws two cards.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Nimbus Swimmer

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

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Psionic Pulse

Counter target noncreature spell. (Then exile this card. You may cast the creature later from exile.)

Sapphire Dragon

Flying
Whenever this creature attacks or blocks, scry 2.

Sapphire Dragon // Psionic Pulse

Blessed Respite

Target player shuffles their graveyard into their library. Prevent all combat damage that would be dealt this turn.

Ride the Shoopuf

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature you control.
{5}{G}{G}: This enchantment becomes a 7/7 Beast creature in addition to its other types.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

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.)

Windstorm

Windstorm deals X damage to each creature with flying.

Aberrant

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Trample
Heavy Power Hammer — Whenever this creature deals combat damage to a player, destroy target artifact or enchantment that player controls.

Stocking the Pantry

Whenever you put one or more +1/+1 counters on a creature you control, put a supply counter on this enchantment.
{2}, Remove a supply counter from this enchantment: Draw a card.

Tendril of the Mycotyrant

{5}{G}{G}: Put seven +1/+1 counters on target noncreature land you control. It becomes a 0/0 Fungus creature with haste. It's still a land.

Sicarian Infiltrator

Flash
Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Benediction of the Omnissiah — When this creature enters, draw a card.

Weatherseed Totem

{T}: Add {G}.
{2}{G}{G}{G}: This artifact becomes a 5/3 green Treefolk artifact creature with trample until end of turn.
When this artifact is put into a graveyard from the battlefield, if it was a creature, return this card to its owner's hand.

Aetherize

Return all attacking creatures to their owner's hand.

Island

Ivy Elemental

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

Ley Weaver

Partner with Lore Weaver (When this creature enters, target player may put Lore Weaver into their hand from their library, then shuffle.)
{T}: Untap two target lands.

Beast Within

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

Roaring Earth

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature or Vehicle you control.
Channel — {X}{G}{G}, Discard this card: Put X +1/+1 counters on target land you control. It becomes a 0/0 green Spirit creature with haste. It's still a land.

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Centaur Glade

{2}{G}{G}: Create a 3/3 green Centaur creature token.

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.

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.

Lakeside Shack

This land enters tapped unless a player has 13 or less life.
{T}: Add {G} or {U}.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Gelatinous Genesis

Wash Out

Return all permanents of the color of your choice to their owners' hands.

Rampant Growth

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

Mother Bear

{3}{G}{G}, Exile this card from your graveyard: Create two 2/2 green Bear creature tokens. Activate only as a sorcery.

Nyxborn Hydra

Bestow {X}{G}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Reach, trample
This permanent enters with X +1/+1 counters on it.
Enchanted creature gets +1/+1 for each +1/+1 counter on this Aura and has reach and trample.

Peel from Reality

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

Spell Burst

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell with mana value X.

Winter Blast

Tap X target creatures. Winter Blast deals 2 damage to each of those creatures with flying.

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.

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.

Spore Cloud

Tap all blocking creatures. Prevent all combat damage that would be dealt this turn. Each attacking creature and each blocking creature doesn't untap during its controller's next untap step.

Hurricane

Hurricane deals X damage to each creature with flying and each player.

Three Visits

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

Treasure Trove

Moment's Peace

Prevent all combat damage that would be dealt this turn.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Serene Sunset

Prevent all combat damage X target creatures would deal this turn.

Counterspell

Open into Wonder

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Wear Down

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Destroy target artifact or enchantment. If the gift was promised, instead destroy two target artifacts and/or enchantments.

Command Tower

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

Prizefight

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Aether Tradewinds

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

Stream of Life

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.

Spinning Wheel Kick

Target creature you control deals damage equal to its power to each of X target creatures and/or planeswalkers.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, this creature gains indestructible until end of turn.

Aether Gale

Return six target nonland permanents to their owners' hands.

Scuttlegator

Defender
{6}{G/U}{G/U}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)
As long as this creature has a +1/+1 counter on it, it can attack as though it didn't have defender.

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.

Distortion Strike

Target creature gets +1/+0 until end of turn and can't be blocked this turn.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Peerless Recycling

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Return target permanent card from your graveyard to your hand. If the gift was promised, instead return two target permanent cards from your graveyard to your hand.

Tangle

Prevent all combat damage that would be dealt this turn.
Each attacking creature doesn't untap during its controller's next untap step.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Forest

Nature's Lore

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

Shifting Wall

Defender (This creature can't attack.)
This creature enters with X +1/+1 counters on it.

Viewpoint Synchronization

Freerunning {2}{G} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Search your library for up to three basic land cards and reveal them. Put two of them onto the battlefield tapped and the other into your hand, then shuffle.

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.

Corrosive Gale

({G/P} can be paid with either {G} or 2 life.)
Corrosive Gale deals X damage to each creature with flying.

Drowned Jungle

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

Drowner of Truth

Devoid (This card has no color.)
When you cast this spell, if {C} was spent to cast it, create two 0/1 colorless Eldrazi Spawn creature tokens with "Sacrifice this token: Add {C}."

Drowner of Truth // Drowned Jungle

Broodguard Elite

This creature enters with X +1/+1 counters on it.
When this creature leaves the battlefield, put its counters on target creature you control.
Warp {X}{G} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Neurok Stealthsuit

Equipped creature has shroud. (It can't be the target of spells or abilities.)
{U}{U}: Attach this Equipment to target creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Wren's Run Hydra

Reach
This creature enters with X +1/+1 counters on it.
Reinforce X—{X}{G}{G} ({X}{G}{G}, Discard this card: Put X +1/+1 counters on target creature.)

Farseek

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

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Vines of Vastwood

Kicker {G} (You may pay an additional {G} as you cast this spell.)
Target creature can't be the target of spells or abilities your opponents control this turn. If this spell was kicked, that creature gets +4/+4 until end of turn.