Wasteland Viper

Deathtouch
Bloodrush — {G}, Discard Wasteland Viper: Target attacking creature gets +1/+2 and gains deathtouch until end of turn.

Corpse Cur

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Corpse Cur enters, you may return target creature card with infect from your graveyard to your hand.

Snake Pit

Whenever an opponent casts a blue or black spell, you may create a 1/1 green Snake creature token.

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Jewel-Eyed Cobra

Deathtouch
When Jewel-Eyed Cobra dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Kaseto, Orochi Archmage

{G}{U}: Target creature can't be blocked this turn. If that creature is a Snake, it gets +2/+2 until end of turn.

Aetherspouts

For each attacking creature, its owner puts it on their choice of the top or bottom of their library.

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.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

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.)

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on it.

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

Ice-Fang Coatl

Flash
Flying
When Ice-Fang Coatl enters, draw a card.
Ice-Fang Coatl has deathtouch as long as you control at least three other snow permanents.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Biomass Mutation

Creatures you control have base power and toughness X/X until end of turn.

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.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn.

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Broodbirth Viper

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Broodbirth Viper deals combat damage to a player, you may draw a card.

Explosive Vegetation

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

Become Immense

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target creature gets +6/+6 until end of turn.

Ambush Viper

Core Prowler

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Core Prowler dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Time of Need

Search your library for a legendary creature card, reveal it, put it into your hand, then shuffle.

Sol Ring

Sabertooth Cobra

Whenever Sabertooth Cobra deals damage to a player, that player gets a poison counter. The player gets another poison counter at the beginning of their next upkeep unless they pay {2} before that step. (A player with ten or more poison counters loses the game.)

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.

Command Tower

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

Winged Coatl

Flash (You may cast this spell any time you could cast an instant.)
Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Kodama's Reach

Fynn, the Fangbearer

Deathtouch
Whenever a creature you control with deathtouch deals combat damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)

Swiftfoot Boots

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

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Seshiro the Anointed

Other Snake creatures you control get +2/+2.
Whenever a Snake you control deals combat damage to a player, you may draw a card.

Chameleon Colossus

Changeling (This card is every creature type.)
Protection from black
{2}{G}{G}: Chameleon Colossus gets +X/+X until end of turn, where X is its power.

Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Beast Within

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

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

One with Nature

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.

Invigorate

If you control a Forest, rather than pay this spell's mana cost, you may have an opponent gain 3 life.
Target creature gets +4/+4 until end of turn.

Novijen, Heart of Progress

{T}: Add {C}.
{G}{U}, {T}: Put a +1/+1 counter on each creature that entered this turn.

Ohran Viper

Whenever Ohran Viper deals combat damage to a creature, destroy that creature at end of combat.
Whenever Ohran Viper deals combat damage to a player, you may draw a card.

Counterspell

Supreme Will

Choose one —
• Counter target spell unless its controller pays {3}.
• Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Moss Viper

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.

Marsh Viper

Whenever Marsh Viper deals damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)

Snow-Covered Forest

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Stoneforge Masterwork

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it.
Equip {2}

Snow-Covered Island

Viridian Corrupter

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Viridian Corrupter enters, destroy target artifact.

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

Triumph of the Hordes

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Blight Mamba

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{1}{G}: Regenerate Blight Mamba.

Phyrexian Swarmlord

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
At the beginning of your upkeep, create a 1/1 green Phyrexian Insect creature token with infect for each poison counter your opponents have.

Kindred Summons

Choose a creature type. Reveal cards from the top of your library until you reveal X creature cards of the chosen type, where X is the number of creatures you control of that type. Put those cards onto the battlefield, then shuffle the rest of the revealed cards into your library.

Sakiko, Mother of Summer

Whenever a creature you control deals combat damage to a player, add that much {G}. Until end of turn, you don't lose this mana as steps and phases end.

Sosuke's Summons

Create two 1/1 green Snake creature tokens.
Whenever a nontoken Snake you control enters, you may return Sosuke's Summons from your graveyard to your hand.

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.