Barry Kripke, PhD (John Ross Bowie) is a colleague working in plasma physics who frequently clashes with Sheldon. Kripke has a case of rhotacism in which he pronounces the letters "R" and "L" as "W" in much the same way as Elmer Fudd from Looney Tunes, Jimmy Five from Monica's Gang and Gilda Radner in her " Baba Wawa " sketches.