Ambush Viper

Boreal Druid

Alloy Myr

Bristling Boar

Bristling Boar can't be blocked by more than one creature.

Brambleweft Behemoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Alpha Tyrranax

Borderland Ranger

When Borderland Ranger enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Ancient Brontodon

Borderland Minotaur

Arcbound Tracker

Menace
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Whenever you cast a spell other than your first spell each turn, put a +1/+1 counter on Arcbound Tracker.

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.)

Ambassador Oak

When Ambassador Oak enters, create a 1/1 green Elf Warrior creature token.

Bannerhide Krushok

Trample
Reinforce 2—{1}{G} ({1}{G}, Discard this card: Put two +1/+1 counters on target creature.)
Scavenge {5}{G}{G} ({5}{G}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Annoyed Altisaur

Reach, trample
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Aerie Ouphes

Sacrifice Aerie Ouphes: It deals damage equal to its power to target creature with flying.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Bloom Hulk

When Bloom Hulk enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Svella, Ice Shaper

{3}, {T}: Create a colorless snow artifact token named Icy Manalith with "{T}: Add one mana of any color."
{6}{R}{G}, {T}: Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Accomplished Automaton

Fabricate 1 (When this creature enters, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)

Ambush Krotiq

Trample
When Ambush Krotiq enters, return another creature you control to its owner's hand.

Arcbound Slasher

Modular 4 (This creature enters with four +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Riot (This creature enters with your choice of an additional +1/+1 counter or haste.)

Bamboo Grove Archer

Defender, reach
Channel — {4}{G}, Discard Bamboo Grove Archer: Destroy target creature with flying.

Baloth Gorger

Kicker {4} (You may pay an additional {4} as you cast this spell.)
If Baloth Gorger was kicked, it enters with three +1/+1 counters on it.