Getting

Mire Boa

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{G}: Regenerate Mire Boa. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Have

Hooded Blightfang

Deathtouch
Whenever a creature you control with deathtouch attacks, each opponent loses 1 life and you gain 1 life.
Whenever a creature you control with deathtouch deals damage to a planeswalker, destroy that planeswalker.

Arcane Signet

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

Mold Adder

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

Rampant Growth

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

Orochi Merge-Keeper

{T}: Add {G}.
As long as Orochi Merge-Keeper is modified, it has "{T}: Add {G}{G}." (Equipment, Auras you control, and counters are modifications.)

Pharika's Mender

When Pharika's Mender enters, you may return target creature or enchantment card from your graveyard to your hand.

Treasured Find

Return target card from your graveyard to your hand. Exile Treasured Find.

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.)

Snake Basket

{X}, Sacrifice Snake Basket: Create X 1/1 green Snake creature tokens. Activate only as a sorcery.

Vraska, Swarm's Eminence

Whenever a creature you control with deathtouch deals damage to a player or planeswalker, put a +1/+1 counter on that creature.
−2: Create a 1/1 black Assassin creature token with deathtouch and "Whenever this creature deals damage to a planeswalker, destroy that planeswalker."

Naga Vitalist

{T}: Add one mana of any type that a land you control could produce.

Hythonia the Cruel

Deathtouch
{6}{B}{B}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Hythonia the Cruel becomes monstrous, destroy all non-Gorgon creatures.

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.)

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.

Marsh Boa

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

River Boa

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{G}: Regenerate River Boa.

Sol Ring

Scourge of the Undercity

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Scourge of the Undercity enters, another target creature you control gains lifelink until end of turn.

Rattleback Apothecary

Deathtouch
Whenever you commit a crime, target creature you control gains your choice of menace or lifelink until end of turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Fynn, the Fangbearer

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
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.)

Gaze of Granite

Destroy each nonland permanent with mana value X or less.

Crypt Cobra

Whenever Crypt Cobra attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Serpent Assassin

When Serpent Assassin enters, you may destroy target nonblack creature.

Skullwinder

Deathtouch
When Skullwinder enters, return target card from your graveyard to your hand, then choose an opponent. That player returns a card from their graveyard to their hand.

Tangle Asp

Whenever Tangle Asp blocks or becomes blocked by a creature, destroy that creature at end of combat.

Pharika, God of Affliction

Indestructible
As long as your devotion to black and green is less than seven, Pharika isn't a creature.
{B}{G}: Exile target creature card from a graveyard. Its owner creates a 1/1 black and green Snake enchantment creature token with deathtouch.

Sakura-Tribe Scout

{T}: You may put a land card from your hand onto the battlefield.

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

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.)

Ankle Biter

Coiled Tinviper

Hornet Cobra

Pharika's Spawn

Escape—{5}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Pharika's Spawn escapes with two +1/+1 counters on it. When it enters this way, each opponent sacrifices a non-Gorgon creature of their choice.

Chevill, Bane of Monsters

Deathtouch
At the beginning of your upkeep, if your opponents control no permanents with bounty counters on them, put a bounty counter on target creature or planeswalker an opponent controls.
Whenever a permanent an opponent controls with a bounty counter on it dies, you gain 3 life and draw a card.

Boa Constrictor

{T}: Boa Constrictor gets +3/+3 until end of turn.

Ohran Frostfang

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

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.)

Forest

Don't Have

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.

Reaper of the Wilds

Whenever another creature dies, scry 1.
{B}: Reaper of the Wilds gains deathtouch until end of turn.
{1}{G}: Reaper of the Wilds gains hexproof until end of turn.

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.

Cobra Trap

If a noncreature permanent under your control was destroyed this turn by a spell or ability an opponent controlled, you may pay {G} rather than pay this spell's mana cost.
Create four 1/1 green Snake creature tokens.

Sosuke, Son of Seshiro

Other Snake creatures you control get +1/+0.
Whenever a Warrior you control deals combat damage to a creature, destroy that creature at end of combat.

Krosan Constrictor

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{T}: Target black creature gets -2/-0 until end of turn.

Dauthi Embrace

{B}{B}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Blasphemous Edict

You may pay {B} rather than pay this spell's mana cost if there are thirteen or more creatures on the battlefield.
Each player sacrifices thirteen creatures of their choice.

Xathrid Gorgon

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
{2}{B}, {T}: Put a petrification counter on target creature. It gains defender and becomes a colorless artifact in addition to its other types. Its activated abilities can't be activated. (A creature with defender can't attack.)

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

Orochi Sustainer

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.

Ambush Viper

Swamp

Pharika's Chosen

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Python

Orochi Soul-Reaver

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token and manifest the top card of that player's library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Darkness

Prevent all combat damage that would be dealt this turn.

Command Tower

Sachi, Daughter of Seshiro

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

Nafs Asp

Whenever Nafs Asp deals damage to a player, that player loses 1 life at the beginning of their next draw step unless they pay {1} before that draw step.

Aphelia, Viper Whisperer

Deathtouch
Whenever Aphelia attacks, you may pay {1}{B/G}. If you do, create a 1/1 black Snake creature token with deathtouch.
{4}{B}: Until end of turn, whenever one or more Gorgons and/or Snakes you control deal combat damage to a player, that player loses half their life, rounded up.

Anaconda

Fang of Shigeki

Skeletal Snake

Moss Viper

Archetype of Finality

Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.

Stonecoil Serpent

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

Wasteland Viper

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