Sasaya's Essence

Whenever a land you control is tapped for mana, add an additional one mana of any type that land produced for each other land you control with the same name as it.

Sasaya, Orochi Ascendant

Reveal your hand: If you have seven or more land cards in your hand, flip Sasaya, Orochi Ascendant.

Sasaya, Orochi Ascendant // Sasaya's Essence

Sakura-Tribe Scout

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

Stonecoil Serpent

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

Sachi, Daughter of Seshiro

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

Sakura-Tribe Elder

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

Jungle Hollow

Jungle Hollow enters the battlefield tapped.
When Jungle Hollow enters the battlefield, you gain 1 life.
{T}: Add {B} or {G}.

Snake Pit

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

Forest

Orochi Hatchery

Orochi Hatchery enters the battlefield with X charge counters on it.
{5}, {T}: Create a 1/1 green Snake creature token for each charge counter on Orochi Hatchery.

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.

Archetype of Finality

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

Prowling Serpopard

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

Foul Orchard

Foul Orchard enters the battlefield tapped.
{T}: Add {B} or {G}.

Swamp

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.

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.)

Seed the Land

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

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.

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.)