Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

Graf Rats

At the beginning of combat on your turn, if you both own and control Graf Rats and a creature named Midnight Scavengers, exile them, then meld them into Chittering Host.

Razortooth Rats

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Macabre Waltz

Return up to two target creature cards from your graveyard to your hand, then discard a card.

Midnight Scavengers

When Midnight Scavengers enters, you may return target creature card with mana value 3 or less from your graveyard to your hand.
(Melds with Graf Rats.)

Barren Moor

Barren Moor enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Murder

Disfigure

Target creature gets -2/-2 until end of turn.

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.)

You Are Already Dead

Destroy target creature that was dealt damage this turn.
Draw a card.

Nezumi Cutthroat

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Nezumi Cutthroat can't block.

Swamp

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)