Valgavoth, Harrower of Souls

Flying
Ward—Pay 2 life.
Whenever an opponent loses life for the first time during each of their turns, put a +1/+1 counter on Valgavoth, Harrower of Souls and draw a card.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Spitfire Lagac

Landfall — Whenever a land you control enters, Spitfire Lagac deals 1 damage to each opponent.

Uncivil Unrest

Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)
If a creature you control with a +1/+1 counter on it would deal damage to a permanent or player, it deals double that damage instead.

Flamecache Gecko

When Flamecache Gecko enters, if an opponent lost life this turn, add {B}{R}.
{1}{R}, Discard a card: Draw a card.

Toxic Iguanar

Toxic Iguanar has deathtouch as long as you control a green permanent. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Hall Monitor

Haste
{1}{R}, {T}: Target creature can't block this turn.

Deathgazer

Whenever Deathgazer blocks or becomes blocked by a nonblack creature, destroy that creature at end of combat.

Hired Claw

Whenever you attack with one or more Lizards, Hired Claw deals 1 damage to target opponent.
{1}{R}: Put a +1/+1 counter on Hired Claw. Activate only if an opponent lost life this turn and only once each turn.

Dagger Caster

When Dagger Caster enters, it deals 1 damage to each opponent and 1 damage to each creature your opponents control.

Valley Flamecaller

If a Lizard, Mouse, Otter, or Raccoon you control would deal damage to a permanent or player, it deals that much damage plus 1 instead.

Kulrath Knight

Flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)
Creatures your opponents control with counters on them can't attack or block.

Mer-Ek Nightblade

Outlast {B} ({B}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has deathtouch.

Magebane Lizard

Whenever a player casts a noncreature spell, Magebane Lizard deals damage to that player equal to the number of noncreature spells they've cast this turn.

Agate Instigator

Offspring {1}{R} (You may pay an additional {1}{R} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever another creature you control enters, this creature deals 1 damage to each opponent.

Extinction Event

Choose odd or even. Exile each creature with mana value of the chosen quality. (Zero is even.)

Gev, Scaled Scorch

Ward—Pay 2 life.
Other creatures you control enter with an additional +1/+1 counter on them for each opponent who lost life this turn.
Whenever you cast a Lizard spell, Gev, Scaled Scorch deals 1 damage to target opponent.

Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature.

Sigiled Skink

Whenever Sigiled Skink attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)