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.

Sosuke's Summons

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

Negate

Steeple Creeper

{3}{U}: Steeple Creeper gains flying until end of turn.

Urban Evolution

Draw three cards. You may play an additional land this turn.

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.)

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Aetherspouts

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

Sylvan Anthem

Green creatures you control get +1/+1.
Whenever a green creature enters the battlefield under your control, scry 1.

Hinterland Harbor

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Snakeform

Until end of turn, target creature loses all abilities and becomes a green Snake with base power and toughness 1/1.
Draw a card.

Scale Deflection

Put two +1/+1 counters on target creature and untap it. It gains hexproof until end of turn. (Then exile this card. You may cast the creature later from exile.)

Dread Linnorm

Dread Linnorm can't be blocked by creatures with power 3 or less.

Dread Linnorm // Scale Deflection

Return to Nature

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

Sachi, Daughter of Seshiro

Other Snake creatures you control get +0/+1.
Shamans you control have "{T}: Add {G}{G}."

Honored Hydra

Trample
Embalm {3}{G} ({3}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Snake Hydra with no mana cost. Embalm only as a sorcery.)

Bone Sabres

Whenever equipped creature attacks, put four +1/+1 counters on it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Ice-Fang Coatl

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

Coiling Stalker

Ninjutsu {1}{G} ({1}{G}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Coiling Stalker deals combat damage to a player, put a +1/+1 counter on target creature you control that doesn't have a +1/+1 counter on it.

Seed the Land

Whenever a land enters the battlefield, its controller creates a 1/1 green Snake creature token.

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.)

Shisato, Whispering Hunter

At the beginning of your upkeep, sacrifice a Snake.
Whenever Shisato, Whispering Hunter deals combat damage to a player, that player skips their next untap step.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

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.

Mold Adder

Whenever an opponent casts a blue or black spell, you may put a +1/+1 counter on Mold Adder.

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.

Hexdrinker

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 3-7
4/4
Protection from instants
LEVEL 8+
6/6
Protection from everything

Endless Swarm

Create a 1/1 green Snake creature token for each card in your hand.
Epic (For the rest of the game, you can't cast spells. At the beginning of each of your upkeeps, copy this spell except for its epic ability.)

Lonis, Cryptozoologist

Whenever another nontoken creature enters the battlefield under your control, 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.

Hornet Cobra

Glass Asp

Whenever Glass Asp deals combat damage to a player, that player loses 2 life at the beginning of their next draw step unless they pay {2} before that step.

Yuan-Ti Malison

Yuan-Ti Malison can't be blocked as long as it's attacking alone.
Whenever Yuan-Ti Malison deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

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}

Prowling Serpopard

This spell can't be countered.
Creature spells you control can't be countered.

Patagia Viper

Flying
When Patagia Viper enters the battlefield, create two 1/1 green and blue Snake creature tokens.
When Patagia Viper enters the battlefield, sacrifice it unless {U} was spent to cast it.

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.)

Ambush Viper

Snow-Covered Forest

Feiyi Snake

Reach (This creature can block creatures with flying.)

Vineglimmer Snarl

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped.
{T}: Add {G} or {U}.

Reflections of Littjara

As Reflections of Littjara enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

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.

Woodland Stream

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

Snow-Covered Island

Time of Need

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

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.)

Temple of Mystery

Temple of Mystery enters the battlefield tapped.
When Temple of Mystery enters the battlefield, scry 1.
{T}: Add {G} or {U}.

Snake Pit

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

Seshiro's Living Legacy

Tales of Master Seshiro

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Put a +1/+1 counter on target creature or Vehicle you control. It gains vigilance until end of turn.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Tales of Master Seshiro // Seshiro's Living Legacy

Lorescale Coatl

Whenever you draw a card, put a +1/+1 counter on Lorescale Coatl.

Serpent Generator

{4}, {T}: Create a 1/1 colorless Snake artifact creature token. It has "Whenever this creature deals damage to a player, that player gets a poison counter." (A player with ten or more poison counters loses the game.)

Fang of Shigeki

Shizuko, Caller of Autumn

At the beginning of each player's upkeep, that player adds {G}{G}{G}. Until end of turn, they don't lose this mana as steps and phases end.

Narnam Cobra

{G}: Narnam Cobra gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Eureka Moment

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

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.

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.

Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Orochi Sustainer

Thirsting Roots

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Blackblade Reforged

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

Counterspell

Nessian Asp

Reach
{6}{G}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)

Overrun

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

Rapid Hybridization

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

Shidako, Broodmistress

{G}, Sacrifice a creature: Target creature gets +3/+3 until end of turn.

Orochi Eggwatcher

{2}{G}, {T}: Create a 1/1 green Snake creature token. If you control ten or more creatures, flip Orochi Eggwatcher.

Orochi Eggwatcher // Shidako, Broodmistress

Coiling Oracle

When Coiling Oracle enters the battlefield, 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.

Vivid Creek

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

Command Tower

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

Broodbirth Viper

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature 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.

Growth Spiral

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

Orochi Leafcaller

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Sakura-Tribe Elder

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

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}.

Simic Signet

Arcane Signet

Lotus Cobra

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

Bite Down

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.

Hooded Hydra

Hooded Hydra enters the battlefield 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.

Moss Viper

Plasm Capture

Counter target spell. At the beginning of your next precombat main phase, add X mana in any combination of colors, where X is that spell's mana value.

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.

Mystic Snake

Flash
When Mystic Snake enters the battlefield, counter target spell.

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.