A rats tribal deck that tries Collected Company, which works well with Relentless Rats. See my mono-black version here: http://tappedout.net/mtg-decks/there-is-a-rat-in-your-pants/ and my budget rats here: http://tappedout.net/mtg-decks/cheap-n-dirty-rats-budget-rat-tribal-46-tix/
Rats
I chose to run 25 creatures because it is a high enough number for Collected Company to work and low enough to allow room for removal and hand disruption.
Ravenous Rats
forces some more discard after a hopefully turn 1 Thoughtseize or Inquisition of Kozilek to make their hand empty of some of their relevant cards.
Pack Rat gets huge turn 4-5 when you play Collected Company. Late game it generates virtual card advantage because you can discard any duds and get big creatures.
Relentless Rats is what you want to hit off of Collected Company for a big army.
Generate an Army
Aether Vial pumps out rats like nothing else, setting up early game extremely aggresively.
Collected Company is just fantastic on turn 4 to get out two extra Relentless Rats in addition to the ones you already have.
Interaction with the Opponent
Abrupt Decay: Nice piece of removal that hits a lot of threats in the format, including non-creature threats.
Dismember: removes most creatures in the format for very cheap.
Thoughtseize and Inquisition of Kozilek are for early discard to deal with threats and removal. I don't know which I like better, so I went half-and-half.
Landbase
Swamp, Verdant Catacombs, and Overgrown Tomb are self-explanatory.
Mutavault pumps up Pack Rat and provides a great blocker too.
Swarmyard keeps your rats safe. Fantastic, absolutely necessary protection.
Urborg, Tomb of Yawgmoth makes the above all tap for black mana if need be. Don't know if 3 or 2 is the right number.
Sideboard
Needs help, Damnation is for creature-based strategies and used to be for Eldrazi,
Oxidize
is for Affinity, Spellskite is mostly for infect, Surgical Extraction is for combo and is absolutely amazing in the dredge match-up, and Pithing Needle is for annoying activated abilities. I want to try to fit in 2xAbrupt Decay.
