Ainok Guide

When Ainok Guide enters, choose one —
• Put a +1/+1 counter on Ainok Guide.
• Search your library for a basic land card, reveal it, then shuffle and put that card on top.

Acid Web Spider

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

Forest

Ajani, Valiant Protector

+2: Put two +1/+1 counters on up to one target creature.
+1: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.
−11: Put X +1/+1 counters on target creature, where X is your life total. That creature gains trample until end of turn.

Aerie Bowmasters

Reach (This creature can block creatures with flying.)
Megamorph {5}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Ajani's Comrade

Trample
At the beginning of combat on your turn, if you control an Ajani planeswalker, put a +1/+1 counter on Ajani's Comrade.

Aerial Predation

Destroy target creature with flying. You gain 2 life.

Abundant Growth

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

Appetite for the Unnatural

Destroy target artifact or enchantment. You gain 2 life.

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.

Advocate of the Beast

At the beginning of your end step, put a +1/+1 counter on target Beast creature you control.