Sinnick is a formerly human marine, now amnesiac and transfigured into the form of an orcish hunter.
Sinnick was a human marine in the Kul Tiras navy during the Third War, and served under Admiral Daelin Proudmoore. When Kul Tiras sent their fleets to Durotar and Dustwallow Marsh to establish a foothold, Sinnick was among their ranks. They established the township on Theramore Isle, and soon after fell under siege by Rexxar and Horde forces. After Admiral Proudmoore's death by Rexxar's hands, most of the Kul Tiras forces fell into retreat to recoup their numbers. They would continue to send their forces to Durotar to bolster their outpost near Razor Hill. Sinnick was eventually sent back to Durotar with one of the fleets, however, the ship he was on never made it to port. The details of their experience is not fully known, but it has been reported that some marines saw a sea witch walking across the sea, and she placed a hex on the crew and ran the ship into the rocks. A majority of the crew died, and the rest disappeared without a trace.
Sinnick later awoke on the southern shore of Durotar with no memory of previous events. He was no longer human, but now had the body and appearance of an Orc. He had been transformed into his most hated enemy. However, due to his amnesia, he had no recollection of his past and was not aware of his transformation. He was accepted into the Valley of Trials and began his training as a hunter.