Hufferton in "LBP" and "Fluff Daddy"

So was Barnab Hufferton supposed to be the reincarnation of some previous character? I heard elsewhere he was Dr. Rainbow, but the Huff character isn’t much like him, and the summary for [i]Magic Baby[/i] said there was a “Dr. R.” in it, so he would be a more probably reincarnation. Lex Gigeroff has played 3-6 characters in 7-11 episodes (depending on which source is accurate), so which one (if any) became Huff?