Akki Ronin

Whenever a Samurai or Warrior you control attacks alone, you may discard a card. If you do, draw a card.

Academy Raider

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever Academy Raider deals combat damage to a player, you may discard a card. If you do, draw a card.

Affectionate Indrik

When Affectionate Indrik enters, you may have it fight target creature you don't control. (Each deals damage equal to its power to the other.)

Ruric Thar, the Unbowed

Vigilance, reach
Ruric Thar, the Unbowed attacks each combat if able.
Whenever a player casts a noncreature spell, Ruric Thar deals 6 damage to that player.

Abzan Beastmaster

At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness.

Akoum Battlesinger

Haste
Whenever Akoum Battlesinger or another Ally you control enters, you may have Ally creatures you control get +1/+0 until end of turn.

Ahn-Crop Crasher

Haste (This creature can attack and {T} as soon as it comes under your control.)
You may exert Ahn-Crop Crasher as it attacks. When you do, target creature can't block this turn. (An exerted creature won't untap during your next untap step.)

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Werewolf Ransacker

Whenever this creature transforms into Werewolf Ransacker, you may destroy target artifact. If that artifact is put into a graveyard this way, Werewolf Ransacker deals 3 damage to that artifact's controller.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Werewolf Ransacker.

Afflicted Deserter

At the beginning of each upkeep, if no spells were cast last turn, transform Afflicted Deserter.

Afflicted Deserter // Werewolf Ransacker

Agitator Ant

At the beginning of your end step, each player may put two +1/+1 counters on a creature they control. Goad each creature that had counters put on it this way. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)