Fleshtaker

Whenever you sacrifice another creature, you gain 1 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{1}, Sacrifice another creature: Fleshtaker gets +2/+2 until end of turn.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Forsaken Sanctuary

Forsaken Sanctuary enters tapped.
{T}: Add {W} or {B}.

Ghoulish Procession

Whenever one or more nontoken creatures die, create a 2/2 black Zombie creature token with decayed. This ability triggers only once each turn. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Shambling Ghast

When Shambling Ghast dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Bladestitched Skaab

Champion of the Perished

Whenever another Zombie you control enters, put a +1/+1 counter on Champion of the Perished.

Swamp

Submerged Boneyard

Submerged Boneyard enters tapped.
{T}: Add {U} or {B}.

Shepherd of the Cosmos

Flying
When Shepherd of the Cosmos enters, return target permanent card with mana value 2 or less from your graveyard to the battlefield.
Foretell {3}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Rampage of the Valkyries

When Rampage of the Valkyries enters, create a 4/4 white Angel creature token with flying and vigilance.
Whenever an Angel you control dies, each other player sacrifices a creature of their choice.