Have

Forest

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.

Mirror Gallery

Kashi-Tribe Elite

Legendary Snakes you control have shroud. (They can't be the targets of spells or abilities.)
Whenever Kashi-Tribe Elite deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Kodama's Reach

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.

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent 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.)

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.

Moss Viper

Strength of Cedars

Target creature gets +X/+X until end of turn, where X is the number of lands you control.

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.

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.)

Sachi, Daughter of Seshiro

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

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

Orochi Sustainer

Tangle Asp

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

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.

Chorus of Might

Until end of turn, target creature gets +1/+1 for each creature you control and gains trample.

Snake Pit

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

Wear Away

Destroy target artifact or enchantment.
Splice onto Arcane {3}{G} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Junkyo Bell

At the beginning of your upkeep, you may have target creature you control get +X/+X until end of turn, where X is the number of creatures you control. If you do, sacrifice that creature at the beginning of the next end step.

Urban Burgeoning

Enchant land
Enchanted land has "Untap this land during each other player's untap step."

Patron of the Orochi

Snake offering (You may cast this spell any time you could cast an instant by sacrificing a Snake and paying the difference in mana costs between this and the sacrificed Snake. Mana cost includes color.)
{T}: Untap all Forests and all green creatures. Activate only once each turn.

Orochi Hatchery

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

Serpent Skin

Flash
Enchant creature
Enchanted creature gets +1/+1.
{G}: Regenerate enchanted creature.

Lure

Enchant creature
All creatures able to block enchanted creature do so.

Natural Order

As an additional cost to cast this spell, sacrifice a green creature.
Search your library for a green creature card, put it onto the battlefield, then shuffle.