It's cartoonish to me. A cartoon Englishman with his monocle and his brandy glass, all wrapped up in tweed and smoking a pipe.
I have never met a
Rupert, not even a dog. The only
Rupert I know about besides
Rupert Murdoch is, years ago the local radio station ran commercials for a used-car parts yard and later a beachfront restaurant, and the pitchman was this guy doing a goofy redneck impersonation and calling himself
Rupert. So I also think of it as a hillbilly cartoonish name.