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.

Feather of Flight

Flash
Enchant creature
When Feather of Flight enters, draw a card.
Enchanted creature gets +1/+0 and has flying.

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.

Brave-Kin Duo

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

Flamecache Gecko

When Flamecache Gecko enters, if an opponent lost life this turn, add {B}{R}.
{1}{R}, Discard a card: Draw a card.

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.

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.

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.

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.)

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.

Intrepid Rabbit

Offspring {1} (You may pay an additional {1} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
When this creature enters, target creature you control gets +1/+1 until end of turn.

Crumb and Get It

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.")
Target creature you control gets +2/+2 until end of turn. If the gift was promised, that creature also gains indestructible until end of turn.

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.

Sazacap's Brew

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
As an additional cost to cast this spell, discard a card.
Target player draws two cards. If the gift was promised, target creature you control gets +2/+0 until end of turn.

Brazen Collector

First strike
Whenever Brazen Collector attacks, add {R}. Until end of turn, you don't lose this mana as steps and phases end.

Thistledown Players

Whenever Thistledown Players attacks, untap target nonland permanent.

Warren Elder

{3}{W}: Creatures you control get +1/+1 until end of turn.

Alania's Pathmaker

When Alania's Pathmaker enters, exile the top card of your library. Until the end of your next turn, you may play that card.

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.

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.

Banishing Light

When Banishing Light enters, exile target nonland permanent an opponent controls until Banishing Light leaves the battlefield.

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.