Catacomb Sifter

Devoid (This card has no color.)
When Catacomb Sifter enters, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."
Whenever another creature you control dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Breeding Pit

At the beginning of your upkeep, sacrifice Breeding Pit unless you pay {B}{B}.
At the beginning of your end step, create a 0/1 black Thrull creature token.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Awakening Zone

At the beginning of your upkeep, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Gristle Grinner

Whenever a creature dies, Gristle Grinner gets +2/+2 until end of turn.

Forest

Vicious Betrayal

As an additional cost to cast this spell, sacrifice any number of creatures.
Target creature gets +2/+2 until end of turn for each creature sacrificed this way.

Essence Harvest

Target player loses X life and you gain X life, where X is the greatest power among creatures you control.

Smothering Abomination

Devoid (This card has no color.)
Flying
At the beginning of your upkeep, sacrifice a creature.
Whenever you sacrifice a creature, draw a card.

Creakwood Liege

Other black creatures you control get +1/+1.
Other green creatures you control get +1/+1.
At the beginning of your upkeep, you may create a 1/1 black and green Worm creature token.

Blasting Station

{T}, Sacrifice a creature: Blasting Station deals 1 damage to any target.
Whenever a creature enters, you may untap Blasting Station.