Abundant Growth

Enchant land
When Abundant Growth enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Aid from the Cowl

Revolt — At the beginning of your end step, if a permanent you controlled left the battlefield this turn, reveal the top card of your library. If it's a permanent card, you may put it onto the battlefield. Otherwise, you may put it on the bottom of your library.

Aberrant

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Trample
Heavy Power Hammer — Whenever Aberrant deals combat damage to a player, destroy target artifact or enchantment that player controls.

Abundance

If you would draw a card, you may instead choose land or nonland and reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and put all other cards revealed this way on the bottom of your library in any order.

Acid Web Spider

Reach
When Acid Web Spider enters, you may destroy target Equipment.

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

Acolyte Hybrid

Heavy Rock Cutter — Whenever Acolyte Hybrid attacks, destroy up to one target artifact. If an artifact is destroyed this way, its controller draws a card.

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.

Abundant Harvest

Choose land or nonland. Reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and the rest on the bottom of your library in a random order.

Adaptive Snapjaw

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)