Yuan-Ti Fang-Blade

Deathtouch
Whenever this creature deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

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.

Ambush Viper

Ankle Biter

Sachi, Daughter of Seshiro

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

Sakura-Tribe Elder

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

Serpent Warrior

When this creature enters, you lose 3 life.

Zombie Boa

{1}{B}: Choose a color. Whenever this creature becomes blocked by a creature of that color this turn, destroy that creature. Activate only as a sorcery.

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.

Shigeki, Jukai Visionary

{1}{G}, {T}, Return Shigeki to its owner's hand: Reveal the top four cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest into your graveyard.
Channel — {X}{X}{G}{G}, Discard this card: Return X target nonlegendary cards from your graveyard to your hand.

Matsu-Tribe Sniper

{T}: This creature deals 1 damage to target creature with flying.
Whenever this creature deals damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Sabertooth Cobra

Whenever this creature 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.)

Prowling Serpopard

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

Sisters of Stone Death

{G}: Target creature blocks Sisters of Stone Death this turn if able.
{B}{G}: Exile target creature blocking or blocked by Sisters of Stone Death.
{2}{B}: Put a creature card exiled with Sisters of Stone Death onto the battlefield under your control.

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.

Kirin-Touched Orochi

Whenever this creature attacks, choose one —
• Exile target creature card from a graveyard. When you do, create a 1/1 colorless Spirit creature token.
• Exile target noncreature card from a graveyard. When you do, put a +1/+1 counter on target creature you control.

Teachings of the Kirin

(As this Saga enters and after your draw step, add a lore counter.)
I — Mill three cards. Create a 1/1 colorless Spirit creature token.
II — Put a +1/+1 counter on target creature you control.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Teachings of the Kirin // Kirin-Touched Orochi

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 this creature.

Orochi Eggwatcher // Shidako, Broodmistress

Erebos's Emissary

Bestow {5}{B} (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 to a creature.)
Discard a creature card: This creature gets +2/+2 until end of turn. If this permanent is an Aura, enchanted creature gets +2/+2 until end of turn instead.
Enchanted creature gets +3/+3.

Pharika's Chosen

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

Orochi Leafcaller

Sakura-Tribe Springcaller

At the beginning of your upkeep, add {G}. Until end of turn, you don't lose this mana as steps and phases end.