Don't Have

Emberheart Challenger

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Valiant — Whenever this creature 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.

Have

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.

Mountain

Mabel, Heir to Cragflame

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

Glittering Massif

({T}: Add {R} or {W}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sheltered by Ghosts

Enchant creature you control
When this Aura enters, exile target nonland permanent an opponent controls until this Aura leaves the battlefield.
Enchanted creature gets +1/+0 and has lifelink and ward {2}.

Stormbeacon Blade

Equipped creature gets +3/+0.
Whenever equipped creature attacks, draw a card if you control three or more attacking creatures.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Heartfire Hero

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

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

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}.)

Whiskervale Forerunner

Valiant — Whenever this creature 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.

Brambleguard Captain

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

Heirloom Blade

Equipped creature gets +3/+1.
Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order.
Equip {1}

Spectator Seating

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

Manifold Mouse

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.

Nettle Guard

Valiant — Whenever this creature 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 this creature: Destroy target artifact or enchantment.

Seedglaive Mentor

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

Sword

Brave-Kin Duo

{1}, {T}: Target creature gets +1/+1 until end of turn. Activate only as a sorcery.

Whiskerquill Scribe

Valiant — Whenever this creature 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.

Cragflame

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

Sacred Peaks

({T}: Add {R} or {W}.)
This land enters tapped.

Temple of Triumph

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {W}.

Thistledown Players

Whenever this creature attacks, untap target nonland permanent.

Raucous Carnival

This land enters tapped unless a player has 13 or less life.
{T}: Add {R} or {W}.

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Furycalm Snarl

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

Mouse Trapper

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

Plains

Blacksmith's Talent

(Gain the next level as a sorcery to add its ability.)
When this Class 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.

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.

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}.)

Slash of Light

Slash of Light deals damage equal to the number of creatures you control plus the number of Equipment you control to target creature.

Roughshod Duo

Trample
Whenever you expend 4, target creature you control gets +1/+1 and gains trample until end of turn. (You expend 4 as you spend your fourth total mana to cast spells during a turn.)

Veteran Guardmouse

Valiant — Whenever this creature 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.)

Radiant Summit

({T}: Add {R} or {W}.)
This land enters tapped unless you control two or more basic lands.

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.