Aspect of Mongoose

Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)
When Aspect of Mongoose is put into a graveyard from the battlefield, return Aspect of Mongoose to its owner's hand.

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters tapped.

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Tranquil Thicket

Tranquil Thicket enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Sachi, Daughter of Seshiro

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

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

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.

Simic Signet

Lorescale Coatl

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

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.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

River Boa

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{G}: Regenerate River Boa.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Orochi Sustainer

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Temple of Mystery

Temple of Mystery enters tapped.
When Temple of Mystery enters, scry 1.
{T}: Add {G} or {U}.

Sakura-Tribe Elder

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Robe of the Archmagi

Whenever equipped creature deals combat damage to a player, you draw that many cards.
Equip {4}
Equip Shaman, Warlock, or Wizard {1}

Broodbirth Viper

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Broodbirth Viper deals combat damage to a player, you may draw a card.

Counterspell

Ohran Frostfang

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

Lonely Sandbar

Lonely Sandbar enters tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Negate

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature you control enters, you may attach Hero's Blade to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Hexdrinker

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 3-7
4/4
Protection from instants
LEVEL 8+
6/6
Protection from everything

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.

Bone Sabres

Whenever equipped creature attacks, put four +1/+1 counters on it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

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.

Wrap in Vigor

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Saryth, the Viper's Fang

Other tapped creatures you control have deathtouch.
Other untapped creatures you control have hexproof.
{1}, {T}: Untap another target creature or land you control.

Perplexing Test

Choose one —
• Return all creature tokens to their owners' hands.
• Return all nontoken creatures to their owners' hands.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Winged Coatl

Flash (You may cast this spell any time you could cast an instant.)
Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Prowling Serpopard

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

Snake Pit

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

Mold Adder

Whenever an opponent casts a blue or black spell, you may put a +1/+1 counter on Mold Adder.

Harmonize

Mosswort Bridge

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Mosswort Bridge enters tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Ice-Fang Coatl

Flash
Flying
When Ice-Fang Coatl enters, draw a card.
Ice-Fang Coatl has deathtouch as long as you control at least three other snow permanents.

Forest

Shigeki, Jukai Visionary

{1}{G}, {T}, Return Shigeki, Jukai Visionary to its owner's hand: Reveal the top four cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest into your graveyard.
Channel — {X}{X}{G}{G}, Discard Shigeki: Return X target nonlegendary cards from your graveyard to your hand.

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, instead tap it, remove it from combat, and heal all damage on it.)

Snake Umbra

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals damage to an opponent, you may draw a card."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Study Hall

{T}: Add {C}.
{1}, {T}: Add one mana of any color. When you spend this mana to cast your commander, scry X, where X is the number of times it's been cast from the command zone this game.

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.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

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.)

Island

Command Tower

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Ambush Viper

Simic Charm

Choose one —
• Target creature gets +3/+3 until end of turn.
• Permanents you control gain hexproof until end of turn.
• Return target creature to its owner's hand.

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Cultivate

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.

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.

Sol Ring

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Lotus Cobra

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

Skullwinder

Deathtouch
When Skullwinder enters, return target card from your graveyard to your hand, then choose an opponent. That player returns a card from their graveyard to their hand.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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.

Aetherspouts

For each attacking creature, its owner puts it on the top or bottom of their library.

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Rampant Growth

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

Blight Mamba

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{1}{G}: Regenerate Blight Mamba.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.