Shadows of the Past

Whenever a creature dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{4}{B}: Each opponent loses 2 life and you gain 2 life. Activate only if there are four or more creature cards in your graveyard.

Snake

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Toshiro Umezawa

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever a creature an opponent controls dies, you may cast target instant card from your graveyard. If that spell would be put into a graveyard, exile it instead.

Primal Vigor

If one or more tokens would be created, twice that many of those tokens are created instead.
If one or more +1/+1 counters would be put on a creature, twice that many +1/+1 counters are put on that creature instead.

Deathgreeter

Whenever another creature dies, you may gain 1 life.

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Dreadhound

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Venomcrawler

Lifelink
Devourer of Souls — Whenever another creature dies, put a +1/+1 counter on this creature.

Pharika, God of Affliction

Indestructible
As long as your devotion to black and green is less than seven, Pharika isn't a creature.
{B}{G}: Exile target creature card from a graveyard. Its owner creates a 1/1 black and green Snake enchantment creature token with deathtouch.

Kamber, the Plunderer

Partner with Laurine, the Diversion (When this creature enters, target player may put Laurine into their hand from their library, then shuffle.)
Lifelink
Whenever a creature an opponent controls dies, you gain 1 life and create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Plague Spitter

At the beginning of your upkeep, this creature deals 1 damage to each creature and each player.
When this creature dies, it deals 1 damage to each creature and each player.

Dross Harvester

Protection from white
At the beginning of your end step, you lose 4 life.
Whenever a creature dies, you gain 2 life.

Blade of the Bloodchief

Whenever a creature dies, put a +1/+1 counter on equipped creature. If equipped creature is a Vampire, put two +1/+1 counters on it instead.
Equip {1}

Grismold, the Dreadsower

Trample
At the beginning of your end step, each player creates a 1/1 green Plant creature token.
Whenever a creature token dies, put a +1/+1 counter on Grismold.

Drivnod, Carnage Dominus

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{B/P}{B/P}, Exile three creature cards from your graveyard: Put an indestructible counter on Drivnod. ({B/P} can be paid with either {B} or 2 life.)

Species Specialist

As this creature enters, choose a creature type.
Whenever a creature of the chosen type dies, you may draw a card.

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Haruspex

Rapacious Hunger — Whenever another creature dies, put a +1/+1 counter on this creature.
Devouring Monster — {T}, Remove X +1/+1 counters from this creature: Add X mana of any one color.

Thornbite Staff

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature."
Whenever a Shaman creature enters, you may attach this Equipment to it.
Equip {4}

Malakir Cullblade

Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature.

Sadistic Glee

Enchant creature
Whenever a creature dies, put a +1/+1 counter on enchanted creature.

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Soul Net

Whenever a creature dies, you may pay {1}. If you do, you gain 1 life.

Sengir, the Dark Baron

Flying
Whenever another creature dies, put two +1/+1 counters on Sengir.
Whenever another player loses the game, you gain life equal to that player's life total as the turn began.
Partner (You can have two commanders if both have partner.)

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Black Market

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Plague Engineer

Deathtouch
As this creature enters, choose a creature type.
Creatures of the chosen type your opponents control get -1/-1.

Engineered Plague

As this enchantment enters, choose a creature type.
All creatures of the chosen type get -1/-1.

Scavenger Drake

Flying
Whenever another creature dies, you may put a +1/+1 counter on this creature.

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis.

Dingus Staff

Whenever a creature dies, this artifact deals 2 damage to that creature's controller.

Swarm of Bloodflies

Flying
This creature enters with two +1/+1 counters on it.
Whenever another creature dies, put a +1/+1 counter on this creature.

Weaver of Harmony

Other enchantment creatures you control get +1/+1.
{G}, {T}: Copy target activated or triggered ability you control from an enchantment source. You may choose new targets for the copy. (Mana abilities can't be targeted.)

Quest for the Gravelord

Whenever a creature dies, you may put a quest counter on this enchantment.
Remove three quest counters from this enchantment and sacrifice it: Create a 5/5 black Zombie Giant creature token.

Falkenrath Noble

Flying
Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Reaper of the Wilds

Whenever another creature dies, scry 1.
{B}: This creature gains deathtouch until end of turn.
{1}{G}: This creature gains hexproof until end of turn.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Bereavement

Whenever a green creature dies, its controller discards a card.

Gristle Grinner

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

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Algae Gharial

Shroud (This creature can't be the target of spells or abilities.)
Whenever another creature dies, you may put a +1/+1 counter on this creature.

Vogar, Necropolis Tyrant

Menace
Whenever another creature dies during your turn, put a +1/+1 counter on Vogar.
When Vogar dies, draw a card for each +1/+1 counter on it.

Cordial Vampire

Whenever this creature or another creature dies, put a +1/+1 counter on each Vampire you control.

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.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Lumberknot

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever a creature dies, put a +1/+1 counter on this creature.