Morbid Opportunist

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

Morkrut Behemoth

As an additional cost to cast this spell, sacrifice a creature or pay {1}{B}.
Menace (This creature can't be blocked except by two or more creatures.)

Necrosynthesis

Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Zombie

No Way Out

Target opponent discards two cards. You create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Novice Occultist

When this creature dies, you draw a card and you lose 1 life.

Olivia's Midnight Ambush

Target creature gets -2/-2 until end of turn. If it's night, that creature gets -13/-13 until end of turn instead.

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.)

Celestus Sanctifier

Day // Night

If it's neither day nor night, it becomes day as this creature enters.
Whenever day becomes night or night becomes day, look at the top two cards of your library. Put one of them into your graveyard.

Shady Traveler // Stalking Predator

The stranger spoke to no one, and the townspeople gladly returned the favor.

Shady Traveler

Menace (This creature can't be blocked except by two or more creatures.)
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Stalking Predator

Menace (This creature can't be blocked except by two or more creatures.)
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Siege Zombie

Tap three untapped creatures you control: Each opponent loses 1 life.

Human

Slaughter Specialist

When this creature enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature.

Stromkirk Bloodthief

At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on target Vampire you control.

Tainted Adversary

Deathtouch
When this creature enters, you may pay {2}{B} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on this creature, then create twice that many 2/2 black Zombie creature tokens with decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Vampire Interloper

As the flames consumed the killer, his eyes remained fixed on the executioner's face, his hands twitching like angry spiders.

Vengeful Strangler

This creature can't block.
When this creature dies, return it to the battlefield transformed under your control attached to target creature or planeswalker an opponent controls.

The next day, the executioner was found with ashen handprints on his throat.

Strangling Grasp

Enchant creature or planeswalker an opponent controls
At the beginning of your upkeep, enchanted permanent's controller sacrifices a nonland permanent of their choice, then that player loses 1 life.

Vengeful Strangler // Strangling Grasp

Abandon the Post

Up to two target creatures can't block this turn.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Innistrad: Double Feature