Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Bellowing Aegisaur

Enrage — Whenever Bellowing Aegisaur is dealt damage, put a +1/+1 counter on each other creature you control.

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

Thrashing Wumpus

{B}: Thrashing Wumpus deals 1 damage to each creature and each player.

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Caltrops

Whenever a creature attacks, Caltrops deals 1 damage to it.

Cacophodon

Enrage — Whenever Cacophodon is dealt damage, untap target permanent.

Stormwild Capridor

Flying
If noncombat damage would be dealt to Stormwild Capridor, prevent that damage. Put a +1/+1 counter on Stormwild Capridor for each 1 damage prevented this way.

Siegehorn Ceratops

Enrage — Whenever Siegehorn Ceratops is dealt damage, put two +1/+1 counters on it. (It must survive the damage to get the counters.)

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Ripjaw Raptor

Enrage — Whenever Ripjaw Raptor is dealt damage, draw a card.

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.