Have

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Swamp

Ghoulcaller's Chant

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target Zombie cards from your graveyard to your hand.

Accursed Marauder

When this creature enters, each player sacrifices a nontoken creature of their choice.

Arms of Hadar

Creatures target player controls get -2/-2 until end of turn.

Mesmeric Fiend

When this creature enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Nested Shambler

When this creature dies, create X tapped 1/1 green Squirrel creature tokens, where X is this creature's power.

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Rotten Reunion

Exile up to one target card from a graveyard. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Drown in Sorrow

All creatures get -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Infestation Sage

When this creature dies, create a 1/1 black and green Insect creature token with flying.

Sylvok Lifestaff

Equipped creature gets +1/+0.
Whenever equipped creature dies, you gain 3 life.
Equip {1}

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Mortician Beetle

Whenever a player sacrifices a creature, you may put a +1/+1 counter on this creature.

Shambling Ghast

When this creature 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 token: Add one mana of any color.")

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.