Q: Which man was the inspiration for Norman Bates, Leatherface, AND Jame Gumb?
A: Ed Gein*
*Should you now choose to Wikipedia "Ed Gein" to see why he was the inspiration for these villains/monsters/things-that-won't die, we need to warn you that there's some pretty disturbing information on his page, not the least of which is Wikipedia's annual fundraising.