Derok was a Klingon and an officer in the Klingon Defense Force in the late 24th century who served on several ships. He was known for moments of cowardice and maintained animosity towards Humans.

In 2373, he served aboard the I.K.S. Hou-Ling and was responsible for dropping the ship's shields when the Borg confronted them. In the latter half of the decade, he served as First officer on the I.K.S. Bochnah, and then, in 2380, was Tactical on the I.K.S. B'Cnah. In 2410, he murdered the ship's cook, discovered warp 10 alien reptilian-salamander spawns of Kathryn Janeway and Tom Paris, and was infected by the Calibus undead-like virus. [Read more]