The overarching subplot has Penrod Pooch (Scatman Crothers, Chico & the Man) testing out a "treasure finder", with the usual disastrous results for Sgt. Flint (Joe E. Ross). Meanwhile, Hong Kong Phooey must tangle with the chameleonic Dr. Disguiso (Don Messick) in the opener, and, then, the Rotten Rainmaker (Paul Winchell) in the second story.
The final episode in the series was a backdoor pilot for Posse Impossible, which would end up going to series 3 years later as a component of C. B. Bears. As you know, C. B. Bears ended up on NBC for its lone season, and the network would acquire reruns of Phooey a couple of years later, creating a rerun block in support of the abysmal Super Globetrotters that also included C. B. Bears repeats, as memory serves.