Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Forest

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.

Ohran Frostfang

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

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.

Sakura-Tribe Elder

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

Prowling Serpopard

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

Fanatic of Rhonas

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}{G}{G}. Activate only if you control a creature with power 4 or greater.
Eternalize {2}{G}{G} ({2}{G}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Snake Druid with no mana cost. Eternalize only as a sorcery.)

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.