Naturalize

Elvish Visionary

When Elvish Visionary enters, draw a card.

Incremental Growth

Put a +1/+1 counter on target creature, two +1/+1 counters on another target creature, and three +1/+1 counters on a third target creature.

Phyrexian Hydra

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
If damage would be dealt to Phyrexian Hydra, prevent that damage. Put a -1/-1 counter on Phyrexian Hydra for each 1 damage prevented this way.

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

Death-Hood Cobra

{1}{G}: Death-Hood Cobra gains reach until end of turn.
{1}{G}: Death-Hood Cobra gains deathtouch until end of turn.

Vines of the Recluse

Target creature gets +1/+2 and gains reach until end of turn. Untap it. (A creature with reach can block creatures with flying.)

Lifecraft Cavalry

Trample
Revolt — Lifecraft Cavalry enters with two +1/+1 counters on it if a permanent you controlled left the battlefield this turn.

Mwonvuli Beast Tracker

When Mwonvuli Beast Tracker enters, search your library for a creature card with deathtouch, hexproof, reach, or trample and reveal it. Shuffle and put that card on top.

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 Hydra Broodmaster becomes monstrous, create X X/X green Hydra creature tokens.

Oran-Rief Invoker

{8}: Oran-Rief Invoker gets +5/+5 and gains trample until end of turn.

Spawnwrithe

Trample
Whenever Spawnwrithe deals combat damage to a player, create a token that's a copy of Spawnwrithe.

Stampeding Elk Herd

Formidable — Whenever Stampeding Elk Herd attacks, if creatures you control have total power 8 or greater, creatures you control gain trample until end of turn.

Oran-Rief Hydra

Trample
Landfall — Whenever a land you control enters, 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.

Lifeblood Hydra

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

Primordial Hydra

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

Feral Hydra

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

Protean Hydra

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

Arbor Elf

Sol Ring

Ravenous Leucrocota

Vigilance
{6}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

Hooded Hydra

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

Neverwinter Hydra

As Neverwinter Hydra enters, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.
Trample
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)

Revive

Return target green card from your graveyard to your hand.

Hydra Omnivore

Whenever Hydra Omnivore deals combat damage to an opponent, it deals that much damage to each other opponent.

Heroes' Bane

Heroes' Bane enters with four +1/+1 counters on it.
{2}{G}{G}: Put X +1/+1 counters on Heroes' Bane, where X is its power.

Chronomaton

{1}, {T}: Put a +1/+1 counter on Chronomaton.

Ironscale Hydra

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

Benevolent Hydra

Benevolent Hydra enters with X +1/+1 counters on it.
If one or more +1/+1 counters would be put on another creature you control, that many plus one +1/+1 counters are put on it instead.
{T}, Remove a +1/+1 counter from Benevolent Hydra: Put a +1/+1 counter on another target creature you control.

Planewide Celebration

Choose four. You may choose the same mode more than once.
• Create a 2/2 Citizen creature token that's all colors.
• Return target permanent card from your graveyard to your hand.
• Proliferate.
• You gain 4 life.

Press the Advantage

Up to two target creatures each get +2/+2 and gain trample until end of turn.

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.
Genesis Hydra enters with X +1/+1 counters on it.

Natural End

Destroy target artifact or enchantment. You gain 3 life.

Ambush Krotiq

Trample
When Ambush Krotiq enters, return another creature you control to its owner's hand.

Iron Apprentice

Iron Apprentice enters with a +1/+1 counter on it.
When Iron Apprentice dies, if it had counters on it, put those counters on target creature you control.

Golden Hind

Capricopian

Capricopian enters with X +1/+1 counters on it.
{2}: Put a +1/+1 counter on Capricopian, then you may reselect which player Capricopian is attacking. Only the player Capricopian is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

Acidic Slime

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

Steelbane Hydra

Steelbane Hydra enters with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from Steelbane Hydra: Destroy target artifact or enchantment.

Clockwork Hydra

Clockwork Hydra enters with four +1/+1 counters on it.
Whenever Clockwork Hydra attacks or blocks, remove a +1/+1 counter from it. If you do, Clockwork Hydra deals 1 damage to any target.
{T}: Put a +1/+1 counter on Clockwork Hydra.

Hungering Hydra

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

Briar Hydra

Trample
Domain — Whenever Briar Hydra deals combat damage to a player, put X +1/+1 counters on target creature you control, where X is the number of basic land types among lands you control.

Vinelasher Kudzu

Landfall — Whenever a land you control enters, put a +1/+1 counter on Vinelasher Kudzu.

Kalonian Hydra

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

Ranger's Path

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

Season of Renewal

Choose one or both —
• Return target creature card from your graveyard to your hand.
• Return target enchantment card from your graveyard to your hand.

Stoic Builder

When Stoic Builder enters, you may return target land card from your graveyard to your hand.

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sandsteppe Mastodon

Reach
When Sandsteppe Mastodon enters, bolster 5. (Choose a creature with the least toughness among creatures you control and put five +1/+1 counters on it.)

Hydra's Growth

Enchant creature
When Hydra's Growth enters, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

Whiptongue Hydra

Reach
When Whiptongue Hydra enters, destroy all creatures with flying. Put a +1/+1 counter on Whiptongue Hydra for each creature destroyed this way.

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Afiya Grove

Afiya Grove enters with three +1/+1 counters on it.
At the beginning of your upkeep, move a +1/+1 counter from Afiya Grove onto target creature.
When Afiya Grove has no +1/+1 counters on it, sacrifice it.

Seek the Wilds

Look at the top four cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Forest

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, Vicious Watcher fights up to one target creature you don't 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 Domesticated Hydra is monstrous, it has trample.