The Reference Desk/Why "Bad Wolf"?

Has Russell T. Davies or anyone associated with Doctor Who ever explained why they chose the concept of "Bad Wolf"? What does it symbolize? Have there been wolf references previously in Doctor Who?

I've looked at lots of DW sources of information but none that explains why Rose looking at the Time Vortex would lead to an identity of being "Bad Wolf". Why is this bad? Or wolfish?

And before the zealous moderators of the Reference Desk exile this simple question to the netherworlds, it was suggested to me by other users to move this question off of the episode pages into this Forum.