Mire Boa

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{G}: Regenerate Mire Boa. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Unsummon

Return target creature to its owner's hand.

Ohran Frostfang

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

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Swarmyard

{T}: Add {C}.
{T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Naga Oracle

When Naga Oracle enters, surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Sudden Reclamation

Mill four cards, then return a creature card and a land card from your graveyard to your hand.

Seer of the Last Tomorrow

{U}, {T}, Discard a card: Target player mills three cards.

Lorescale Coatl

Whenever you draw a card, put a +1/+1 counter on Lorescale Coatl.

Kaseto, Orochi Archmage

{G}{U}: Target creature can't be blocked this turn. If that creature is a Snake, it gets +2/+2 until end of turn.

Rhonas's Monument

Green creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.

Naga Vitalist

{T}: Add one mana of any type that a land you control could produce.

Will of the Naga

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Sinuous Striker

{U}: Sinuous Striker gets +1/-1 until end of turn.
Eternalize—{3}{U}{U}, Discard a card. ({3}{U}{U}, Discard a card, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Snake Warrior with no mana cost. Eternalize only as a sorcery.)

Anaconda

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Spellweaver Eternal

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)

Sagu Archer

Reach (This creature can block creatures with flying.)
Morph {4}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Shed Weakness

Target creature gets +2/+2 until end of turn. You may remove a -1/-1 counter from it.

Venomous Fangs

Enchant creature
Whenever enchanted creature deals damage to a creature, destroy the other creature.

Slither Blade

Naga Eternal

Narnam Cobra

{G}: Narnam Cobra gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Forest

Steeple Creeper

{3}{U}: Steeple Creeper gains flying until end of turn.

Sabertooth Cobra

Whenever Sabertooth Cobra 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.)

Aluren

Any player may cast creature spells with mana value 3 or less without paying their mana costs and as though they had flash.

Sidisi's Faithful

Exploit (When this creature enters, you may sacrifice a creature.)
When Sidisi's Faithful exploits a creature, return target creature to its owner's hand.

Marsh Viper

Whenever Marsh Viper deals damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)

Sultai Skullkeeper

When Sultai Skullkeeper enters, mill two cards.

Noose Constrictor

Reach
Discard a card: Noose Constrictor gets +1/+1 until end of turn.

Psychic Venom

Enchant land
Whenever enchanted land becomes tapped, Psychic Venom deals 2 damage to that land's controller.

Venom

Enchant creature
Whenever enchanted creature blocks or becomes blocked by a non-Wall creature, destroy the other creature at end of combat.

Watchful Naga

You may exert Watchful Naga as it attacks. When you do, draw a card. (An exerted creature won't untap during your next untap step.)

Moss Viper

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Tah-Crop Skirmisher

Embalm {3}{U} ({3}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Snake Warrior with no mana cost. Embalm only as a sorcery.)

Ambush Viper

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Sickleslicer

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +2/+2.
Equip {4}

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

Sakura-Tribe Elder

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