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.

Cadaver Imp

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

Liliana's Specter

Flying
When Liliana's Specter enters, each opponent discards a card.

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}: Order of the Ebon Hand gains first strike until end of turn.
{B}{B}: Order of the Ebon Hand gets +1/+0 until end of turn.

Fog of Gnats

Gray Merchant of Asphodel

When Gray Merchant of Asphodel 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.)

Cuombajj Witches

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

Chittering Rats

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

Vampire Sovereign

Flying
When Vampire Sovereign enters, target opponent loses 3 life and you gain 3 life.