Mage Slayer

Whenever equipped creature attacks, it deals damage equal to its power to the player or planeswalker it's attacking.
Equip {3}

Kutzil, Malamet Exemplar

Your opponents can't cast spells during your turn.
Whenever one or more creatures you control each with power greater than its base power deals combat damage to a player, draw a card.

Tiller of Flesh

Whenever you cast a spell that targets one or more permanents, incubate 2. (Create an Incubator token with two +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)

Labyrinth Champion

Heroic — Whenever you cast a spell that targets this creature, this creature deals 2 damage to any target.

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.

Tomik, Distinguished Advokist

Flying
Lands on the battlefield and land cards in graveyards can't be the targets of spells or abilities your opponents control.
Your opponents can't play land cards from graveyards.

Favored Hoplite

Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature and prevent all damage that would be dealt to it this turn.

Calamity Bearer

If a Giant source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

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}.

Brave-Kin Duo

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

Reyav, Master Smith

Whenever a creature you control that's enchanted or equipped attacks, that creature gains double strike until end of turn.

Boltbender

Disguise {1}{R} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, you may choose new targets for any number of other spells and/or abilities.

Astor, Bearer of Blades

When Astor enters, look at the top seven cards of your library. You may reveal an Equipment or Vehicle card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Equipment you control have equip {1}.
Vehicles you control have crew 1.

Ertha Jo, Frontier Mentor

When Ertha Jo enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
Whenever you activate an ability that targets a creature or player, copy that ability. You may choose new targets for the copy.

Fabled Hero

Double strike
Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on it.

Legolas, Master Archer

Reach
Whenever you cast a spell that targets Legolas, put a +1/+1 counter on Legolas.
Whenever you cast a spell that targets a creature you don't control, Legolas deals damage equal to its power to up to one target creature.

Anax and Cymede

First strike, vigilance
Heroic — Whenever you cast a spell that targets Anax and Cymede, creatures you control get +1/+1 and gain trample until end of turn.

Feather, Radiant Arbiter

Flying, lifelink
Whenever you cast a noncreature spell that targets only Feather, you may choose any number of other creatures that spell could target and pay {2} for each of those creatures. If you do, for each of those creatures, copy that spell. The copy targets that creature. (Copies of permanent spells become tokens.)

Standard Bearer

While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.

Thistledown Players

Whenever this creature attacks, untap target nonland permanent.

Dawnbringer Charioteers

Flying, lifelink
Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature.

Hero of the Nyxborn

When this creature enters, create a 1/1 white Human Soldier creature token.
Whenever you cast a spell that targets this creature, creatures you control get +1/+0 until end of turn.

Arcee, Acrobatic Coupe

Living metal (During your turn, this Vehicle is also a creature.)
Whenever you cast a spell that targets one or more creatures or Vehicles you control, put that many +1/+1 counters on Arcee. Convert Arcee.

Arcee, Sharpshooter

More Than Meets the Eye {R}{W} (You may cast this card converted for {R}{W}.)
First strike
{1}, Remove one or more +1/+1 counters from Arcee: It deals that much damage to target creature. Convert Arcee.

Arcee, Sharpshooter // Arcee, Acrobatic Coupe

Minsc, Beloved Ranger

When Minsc enters, create Boo, a legendary 1/1 red Hamster creature token with trample and haste.
{X}: Until end of turn, target creature you control has base power and toughness X/X and becomes a Giant in addition to its other types. Activate 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.

Mirror-Shield Hoplite

Vigilance
Whenever a creature you control becomes the target of a backup ability, copy that ability. You may choose new targets for the copy. This ability triggers only once each turn.

Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

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.

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.

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

Weaver of Harmony

Other enchantment creatures you control get +1/+1.
{G}, {T}: Copy target activated or triggered ability you control from an enchantment source. You may choose new targets for the copy. (Mana abilities can't be targeted.)

Precursor Golem

When this creature enters, create two 3/3 colorless Golem artifact creature tokens.
Whenever a player casts an instant or sorcery spell that targets only a single Golem, that player copies that spell for each other Golem that spell could target. Each copy targets a different one of those Golems.

Danitha, New Benalia's Light

Vigilance, trample, lifelink
Once during each of your turns, you may cast an Aura or Equipment spell from your graveyard.

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.

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.

Pearl-Ear, Imperial Advisor

Lifelink
Enchantment spells you cast have affinity for Auras. (They cost {1} less to cast for each Aura you control.)
Whenever you cast an Aura spell that targets a modified permanent you control, draw a card. (Equipment, Auras you control, and counters are modifications.)

Vigilant Martyr

Sacrifice this creature: Regenerate target creature.
{W}{W}, {T}, Sacrifice this creature: Counter target spell that targets an enchantment.

Phalanx Leader

Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on each creature you control.