This deck, based off another budget standard deck, gave me an idea to improve it further more. Now introducing in the deck, Pack Rat, a great Rat addition to this deck. As you flood the board with Rat Colony, you get to increase the power of all of your rats, and even multiply Pack Rat to get some big beaters on the board.
For disruption, I've added something a little bit of hand control to prevent players from calling the exterminator. Disrupts are Smallpox and Raven's Crime.
To call upon our friendly little rats, and to give them enough strength to work together as a pack, there is Bontu's Monument, Secret Salvage, Altar's Reap, Vanquisher's Banner, Whip of Erebos and Bad Moon.
I've balanced out a bit the number of creatures in this deck so you don't end up drawing only the rats. You actually get a chance to play the more supportive or disruptive cards and set up a very powerful board while still being capable of sending out rats efficiently and quickly. You get lots of heals from Whip of Erebos, and lots of power to simple 1 cost rats with the help of Bontu's Monument. Plus, if a Pack Rat is in the grave, you can bring it back with the whip and duplicate it before it is exiled.
If you find that the lands are too much, you can always make a swap with card draw or such as a fourth copy of Altar's Reap or some disruption like mono-black card destruction or even a tutor or two.
Suggestions are always appreciated. I'd like to try and keep it budget if possible, or to have a decent threshold of how expensive the cards should be.
-Based off the standard deck http://tappedout.net/mtg-decks/mono-black-plauge/
