Swamp

Unruly Mob

Whenever another creature you control dies, put a +1/+1 counter on Unruly Mob.

Novice Occultist

When Novice Occultist dies, you draw a card and you lose 1 life.

Plains

Cathar Commando

Flash (You may cast this spell any time you could cast an instant.)
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Awoken Demon

Ecstatic Awakener

{2}{B}, Sacrifice another creature: Draw a card, then transform Ecstatic Awakener. Activate only once each turn.

Ecstatic Awakener // Awoken Demon

Carrier Thrall

When Carrier Thrall dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Thraxodemon

{3}, {T}, Sacrifice another creature or artifact: Draw a card.

Nasty End

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards. If the sacrificed creature was legendary, draw three cards instead.

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

Stirge

Flying
Stirge can't block.
Blood Drain — {1}{B}, Pay 1 life, Sacrifice Stirge: Draw a card.

Voracious Vermin

When Voracious Vermin enters, create a 1/1 black Rat creature token with "This creature can't block."
Whenever another creature you control dies, put a +1/+1 counter on Voracious Vermin.

Tormod's Cryptkeeper

Vigilance
{T}, Sacrifice Tormod's Cryptkeeper: Exile target player's graveyard.

Death's-Head Buzzard

Flying
When Death's-Head Buzzard dies, all creatures get -1/-1 until end of turn.

Guardian Kirin

Flying
Whenever another creature you control dies, put a +1/+1 counter on Guardian Kirin.