Many thanks for your comments. I've seen "leventy-leven" meaning 111 or 121 so far. Anyway, the soumd has a nice ring compared to "one hundred and eleven" or "one hundred and twenty-one" .
Maybe cartoon characters have eight fingers at least for a technical reason.
Well, "lebenty-leben" seems rather rare for English speaking people, right? I wonder if there is a possibility that the phrase appeared in "Song of the South" in conversation, but I have no means to find out...