Rhakh-tem

Rhakh-tem was a Professor and Klingon neurobiologist at Starfleet Medical Academy in the 2360s. Rhakh-tem often feuded with Selok. Julian Bashir recalled that Rhakh-tem had never thrown anything larger than a retort (the glass kind) at Selok, but Selok always caught it. 

It is not clear whether Rhakh-tem was a Klingon, or just an expert in Klingon neurobiology.