This is purely theory-crafted as of the moment, as I have no budget to purchase these cards nor do I have a computer on which to test this deck. That being said, this is something I conjured up for the standard season.
Den Protector and Deathmist Raptor are a nice tag-team. 5 mana for a Regrowth, a 3/2, and up to four 3/3s that trade up. That's value!
Rakshasa Deathdealer causes headaches for early attempts at removal. Thoughtseize into Demon-Kitty is a nice way to start the game.
Courser of Kruphix helps us filter lands off the top and provides recovery from Thoughtseize life loss. We also have a pair of Sidisi, Undead Vizier, who has a tutor and a kill/6 body for five. Not too shabby!
Ruthless Ripper is our utility one-drop. She unmorphs for free, trades up, or stays a 2/2.
Lastly, a pair of Hooded Hydras make great exploit targets and scale well into the late game.
We finish up the numbers with a dash of the premium removal black has access to, and a miser's Life's Legacy for testing purposes.
The sideboard probably will change as I find more efficient answers to the problems the deck will face.
Please comment with any suggestions you deem appropriate; I'd like to keep the deck straight G/B if possible so I'm not forced to run 4x Siege Rhino.