Strength of Cedars

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

Forest

Kashi-Tribe Reaver

Whenever Kashi-Tribe Reaver deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.
{1}{G}: Regenerate Kashi-Tribe Reaver.

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.

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.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

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.

Orochi Ranger

Whenever Orochi Ranger deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Sakura-Tribe Elder

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

Kashi-Tribe Warriors

Whenever Kashi-Tribe Warriors deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

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.)

Sachi, Daughter of Seshiro

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

Serpent Skin

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

Hankyu

Equipped creature has "{T}: Put an aim counter on Hankyu" and "{T}, Remove all aim counters from Hankyu: This creature deals damage to any target equal to the number of aim counters removed this way."
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

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

Lure

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

Matsu-Tribe Decoy

{2}{G}: Target creature blocks Matsu-Tribe Decoy this turn if able.
Whenever Matsu-Tribe Decoy deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Time of Need

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