Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Rapacious Guest

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Food token.
Whenever you sacrifice a Food, put a +1/+1 counter on Rapacious Guest.
When Rapacious Guest leaves the battlefield, target opponent loses life equal to its power.

Gilt-Leaf Winnower

Menace (This creature can't be blocked except by two or more creatures.)
When Gilt-Leaf Winnower enters, you may destroy target non-Elf creature whose power and toughness aren't equal.

Cairn Wanderer

Changeling (This card is every creature type.)
As long as a creature card with flying is in a graveyard, Cairn Wanderer has flying. The same is true for fear, first strike, double strike, deathtouch, haste, landwalk, lifelink, protection, reach, trample, shroud, and vigilance.

Ophiomancer

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

Ruthless Winnower

At the beginning of each player's upkeep, that player sacrifices a non-Elf creature of their choice.

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.