Chittering Rats

When this creature enters, target opponent puts a card from their hand on top of their library.

Rathi Intimidator

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{2}, {T}: Search your library for a Mercenary permanent card with mana value 2 or less, put it onto the battlefield, then shuffle.

Cateran Persuader

{1}, {T}: Search your library for a Mercenary permanent card with mana value 1 or less, put it onto the battlefield, then shuffle.

Order of the Ebon Hand

Protection from white
{B}: This creature gains first strike until end of turn.
{B}{B}: This creature gets +1/+0 until end of turn.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Vampire Sovereign

Flying
When this creature enters, target opponent loses 3 life and you gain 3 life.

Cadaver Imp

Flying
When this creature enters, you may return target creature card from your graveyard to your hand.

Liliana's Specter

Flying
When this creature enters, each opponent discards a card.

Cuombajj Witches

{T}: This creature deals 1 damage to any target and 1 damage to any target of an opponent's choice.