Mono-Black Relentless Rats deck.
Creatures
Since it is a Relentless Rat deck, of course there are Relentless Rats. Currently there are 15, but I can bump it up to 19 by moving Septic Rats out.
Ravenous Rats are fun and cheap, getting my opponent to discard a card.
Marrow-Gnawer is there to give my rats fear and can sac a Rat to increase my army.
Phage is there to intimidate my opponent a bit.
Artifacts
Thrumming Stone is there for its synergy with Relentless Rats.
Planeswalker
Liliana Vess is there to give my opponent something to attack.
Sorceries
Exsanguinate for big group decks, or sap the last of my opponent's health.
Infest works well with Sudden Spoiling, although I wish it were instant. If I have more than two Relentless, they'll survive.
Instants
Dark Ritual for mana excel. Can be used to get first turn Thrumming Stone or Phage.
Grasp of Darkness for creature kill.
Sacrifice for additional mana. Instant speed, so I can use a creature that might die to play Grasp of Darkness or Sudden Spoiling.
Sudden Spoiling is to help when my opponent has a lot of creatures attacking or blocking. Works well with Infest.
Lands
Swamp, since I'm playing mono-black. When I get more Cabal Coffers and Urborg, I'll take some Swamps out to replace them.
Crypt of Agadeem is not as good as Cabal Coffers and can be taken out when better options are available. Really great when my Opponent kills my creatures, though, though I'd prefer my creatures being in play.
Swarmyard is there to regenerate my Rats.
