Swamp

Unruly Mob

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

Plains

Hobbling Zombie

Deathtouch
When this creature dies, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

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.

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.

Dauntless Avenger

Whenever this creature attacks, return target creature card with mana value 2 or less from your graveyard to the battlefield tapped and attacking.

Bereaved Survivor

When another creature you control dies, transform this creature.

Bereaved Survivor // Dauntless Avenger

Novice Occultist

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

Arrogant Outlaw

When this creature enters, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.

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.)

Candlegrove Witch

Coven — At the beginning of combat on your turn, if you control three or more creatures with different powers, this creature gains flying until end of turn.

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: This creature gets +2/+2 until end of turn.

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.)

Cathar's Call

Enchant creature
Enchanted creature has vigilance and "At the beginning of your end step, create a 1/1 white Human creature token."

Seasoned Cathar

Ambitious Farmhand

When this creature enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
Coven — {1}{W}{W}: Transform this creature. Activate only if you control three or more creatures with different powers.

Ambitious Farmhand // Seasoned Cathar

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.)

Blessed Defiance

Target creature you control gets +2/+0 and gains lifelink until end of turn. When that creature dies this turn, create a 1/1 white Spirit creature token with flying.

Ritual Guardian

Coven — At the beginning of combat on your turn, if you control three or more creatures with different powers, this creature gains lifelink until end of turn.