The Informer - S1-E1
Other mistake: Klink has on his monocle, as usual. If you look closely, the monocle is a single lens, with no frame. From Episode 2 onward, the monocle has a frame and a gallery. Also, Klink wears it at an angle, not unlike the Penguin in the original Batman series, who also wore a monocle without a frame.
Answer: Nimrod's actual identity was never revealed in the series. It was only known that he was a British intelligence agent. Nimrod was not Colonel Klink. Hogan had only implied it was him as a ruse to get Klink returned as camp commandant, not wanting him replaced by someone more competent who would impede the Heroes war activities. (As another contributor previously posted, the term "nimrod" is slang for a nerdy, doofus type of person, though it's unclear why that was his code name).
raywest ★