Breakneck Berserker

Frost Bite

Frost Bite deals 2 damage to target creature or planeswalker. If you control three or more snow permanents, it deals 3 damage instead.

Tuskeri Firewalker

Boast — {1}: Exile the top card of your library. You may play that card this turn. (Activate only if this creature attacked this turn and only once each turn.)

Arc Lightning

Arc Lightning deals 3 damage divided as you choose among one, two, or three targets.

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Tok-Tok, Volcano Born

Protection from red
If a red source would deal damage to a player, it deals that much damage plus 1 to that player instead.

Akki Lavarunner

Haste
Whenever Akki Lavarunner deals damage to an opponent, flip it.

Akki Lavarunner // Tok-Tok, Volcano Born

Arni Brokenbrow

Haste
Boast — {1}: You may change Arni Brokenbrow's base power to 1 plus the greatest power among other creatures you control until end of turn. (Activate only if this creature attacked this turn and only once each turn.)

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Goldspan Dragon

Flying, haste
Whenever Goldspan Dragon attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Mardu Heart-Piercer

Raid — When Mardu Heart-Piercer enters, if you attacked this turn, Mardu Heart-Piercer deals 2 damage to any target.

Glacial Ray

Glacial Ray deals 2 damage to any target.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Tormenting Voice

As an additional cost to cast this spell, discard a card.
Draw two cards.

Goblinslide

Whenever you cast a noncreature spell, you may pay {1}. If you do, create a 1/1 red Goblin creature token with haste.

Snow-Covered Mountain

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Valley Dasher

Haste
Valley Dasher attacks each combat if able.

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.