Plains

Canyon Jerboa

Landfall — Whenever a land you control enters, creatures you control get +1/+1 until end of turn.

Elspeth, Sun's Champion

+1: Create three 1/1 white Soldier creature tokens.
−3: Destroy all creatures with power 4 or greater.
−7: You get an emblem with "Creatures you control get +2/+2 and have flying."

Sol Ring

Seedglaive Mentor

Vigilance, haste
Valiant — Whenever Seedglaive Mentor becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.

Mabel, Heir to Cragflame

Other Mice you control get +1/+1.
When Mabel, Heir to Cragflame enters, create Cragflame, a legendary colorless Equipment artifact token with "Equipped creature gets +1/+1 and has vigilance, trample, and haste" and equip {2}.

Boros Signet

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Cragflame

Equipped creature gets +1/+1 and has vigilance, trample, and haste.
Equip {2}

Lupinflower Village

{T}: Add {C}.
{T}: Add {W}. Spend this mana only to cast a creature spell.
{1}{W}, {T}, Sacrifice Lupinflower Village: Look at the top six cards of your library. You may reveal a Bat, Bird, Mouse, or Rabbit card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Martial Impetus

Enchant creature
Enchanted creature gets +1/+1 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, each other creature that's attacking one of your opponents gets +1/+1 until end of turn.

Might of the Meek

Target creature gains trample until end of turn. It also gets +1/+0 until end of turn if you control a Mouse.
Draw a card.

Steelburr Champion

Vigilance
Whenever an opponent casts a noncreature spell, put a +1/+1 counter on this creature. (This token's mana cost is {2}{W}.)

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Veteran Guardmouse

Valiant — Whenever Veteran Guardmouse becomes the target of a spell or ability you control for the first time each turn, it gets +1/+0 and gains first strike until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Mabel's Mettle

Target creature gets +2/+2 until end of turn. Up to one other target creature gets +1/+1 until end of turn.

Whiskervale Forerunner

Valiant — Whenever Whiskervale Forerunner becomes the target of a spell or ability you control for the first time each turn, look at the top five cards of your library. You may reveal a creature card with mana value 3 or less from among them. You may put it onto the battlefield if it's your turn. If you don't put it onto the battlefield, put it into your hand. Put the rest on the bottom of your library in a random order.

Flowerfoot Swordmaster

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, Mice you control get +1/+0 until end of turn.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Sword

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Food

{2}, {T}, Sacrifice this artifact: You gain 3 life.

Soldier

Command Tower

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

Brambleguard Captain

At the beginning of combat on your turn, target creature you control gets +X/+0 until end of turn, where X is Brambleguard Captain's power.

Valley Rally

Gift a Food (You may promise an opponent a gift as you cast this spell. If you do, they create a Food token before its other effects. It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Creatures you control get +2/+0 until end of turn. If the gift was promised, target creature you control gains first strike until end of turn.

Brightblade Stoat

Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, Mice you control get +1/+0 until end of turn.
(This token's mana cost is {W}.)

Blacksmith's Talent

(Gain the next level as a sorcery to add its ability.)
When Blacksmith's Talent enters, create a colorless Equipment artifact token named Sword with "Equipped creature gets +1/+1" and equip {2}.
{2}{R}: Level 2
At the beginning of combat on your turn, attach target Equipment you control to up to one target creature you control.
{3}{R}: Level 3
During your turn, equipped creatures you control have double strike and haste.

Rockface Village

{T}: Add {C}.
{T}: Add {R}. Spend this mana only to cast a creature spell.
{R}, {T}: Target Lizard, Mouse, Otter, or Raccoon you control gets +1/+0 and gains haste until end of turn. Activate only as a sorcery.

Dewdrop Cure

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Return up to two target creature cards each with mana value 2 or less from your graveyard to the battlefield. If the gift was promised, instead return up to three target creature cards each with mana value 2 or less from your graveyard to the battlefield.

Manifold Mouse

At the beginning of combat on your turn, target Mouse you control gains your choice of double strike or trample until end of turn.
(This token's mana cost is {1}{R}.)

Three Blind Mice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Create a 1/1 white Mouse creature token.
II, III — Create a token that's a copy of target token you control.
IV — Creatures you control get +1/+1 and gain vigilance until end of turn.

Thistledown Players

Whenever Thistledown Players attacks, untap target nonland permanent.

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Banner of Kinship

As this artifact enters, choose a creature type. This artifact enters with a fellowship counter on it for each creature you control of the chosen type.
Creatures you control of the chosen type get +1/+1 for each fellowship counter on this artifact.

Emberheart Challenger

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Valiant — Whenever Emberheart Challenger becomes the target of a spell or ability you control for the first time each turn, exile the top card of your library. Until end of turn, you may play that card.

Calamity of Cinders

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Calamity of Cinders deals 6 damage to each untapped creature.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Rabid Gnaw

Target creature you control gets +1/+0 until end of turn. Then it deals damage equal to its power to target creature you don't control.

Exotic Orchard

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

Slayers' Stronghold

{T}: Add {C}.
{R}{W}, {T}: Target creature gets +2/+0 and gains vigilance and haste until end of turn.

Arcane Signet

Squeak By

Target creature you control gets +1/+1 until end of turn. It can't be blocked by creatures with power 3 or greater this turn.

Cheeky House-Mouse

Cheeky House-Mouse // Squeak By

Elephant

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.

Dawn's Truce

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
You and permanents you control gain hexproof until end of turn. If the gift was promised, permanents you control also gain indestructible until end of turn.

Rugged Prairie

{T}: Add {C}.
{R/W}, {T}: Add {R}{R}, {R}{W}, or {W}{W}.

Whiskerquill Scribe

Valiant — Whenever Whiskerquill Scribe becomes the target of a spell or ability you control for the first time each turn, you may discard a card. If you do, draw a card.

Mountain

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Pests of Honor

Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, put a +1/+1 counter on Pests of Honor.

War Squeak

Enchant creature
When War Squeak enters, target creature an opponent controls can't block this turn.
Enchanted creature gets +1/+1 and has haste.

Armory Mice

Celebration — Armory Mice gets +0/+2 as long as two or more nonland permanents entered the battlefield under your control this turn.

Festival of Embers

During your turn, you may cast instant and sorcery spells from your graveyard by paying 1 life in addition to their other costs.
If a card or token would be put into your graveyard from anywhere, exile it instead.
{1}{R}: Sacrifice Festival of Embers.

Jolly Gerbils

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. Talisman of Conviction deals 1 damage to you.

Mouse

Furycalm Snarl

As Furycalm Snarl enters, you may reveal a Mountain or Plains card from your hand. If you don't, Furycalm Snarl enters tapped.
{T}: Add {R} or {W}.

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Generous Gift

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

Nettle Guard

Valiant — Whenever Nettle Guard becomes the target of a spell or ability you control for the first time each turn, it gets +0/+2 until end of turn.
{1}, Sacrifice Nettle Guard: Destroy target artifact or enchantment.

Treasure

{T}, Sacrifice this artifact: Add one mana of any color.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Sword of the Squeak

Equipped creature gets +1/+1 for each creature you control with base power or toughness 1.
Whenever a Hamster, Mouse, Rat, or Squirrel you control enters, you may attach Sword of the Squeak to that creature.
Equip {2}

Mouse Trapper

Flash
Valiant — Whenever Mouse Trapper becomes the target of a spell or ability you control for the first time each turn, tap target creature an opponent controls.

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
At the beginning of combat on your turn, target Mouse you control gains your choice of double strike or trample until end of turn.

Repel Calamity

Destroy target creature with power or toughness 4 or greater.

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)

Heartfire Hero

Valiant — Whenever Heartfire Hero becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.
When Heartfire Hero dies, it deals damage equal to its power to each opponent.

Offspring {1}{W} (You may pay an additional {1}{W} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Vigilance
Whenever an opponent casts a noncreature spell, put a +1/+1 counter on this creature.

Raging Battle Mouse

The second spell you cast each turn costs {1} less to cast.
Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+1 until end of turn.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Echoing Assault

Creature tokens you control have menace.
Whenever you attack a player, choose target nontoken creature that's attacking that player. Create a token that's a copy of that creature, except it's 1/1. The token enters tapped and attacking that player. Sacrifice it at the beginning of the next end step.

Season of the Bold

Choose up to five {P} worth of modes. You may choose the same mode more than once.
{P} — Create a tapped Treasure token.
{P}{P} — Exile the top two cards of your library. Until the end of your next turn, you may play them.
{P}{P}{P} — Until the end of your next turn, whenever you cast a spell, Season of the Bold deals 2 damage to up to one target creature.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Temple of Triumph

Temple of Triumph enters tapped.
When Temple of Triumph enters, scry 1.
{T}: Add {R} or {W}.

Blooming Blast

Gift a Treasure (You may promise an opponent a gift as you cast this spell. If you do, they create a Treasure token before its other effects. It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Blooming Blast deals 2 damage to target creature. If the gift was promised, Blooming Blast also deals 3 damage to that creature's controller.