A Chokuzan Commander
The Chokuzan may be a humanoid species native to the Delta Quadrant, however, they may be a fictional race created by Q.
In 2377, while Q (junior) was under Captain Janeway's care, he stole the Delta Flyer and took Icheb off through a multispacial fissure. Once they exited it, far from Voyager, they were hailed by a Chokuzan warship, who ordered them to surrender their vessel, as they were in their space. The Chokuzan fired a weapon which injured Icheb with omicron radiation, and the Delta Flyer returned to Voyager.
Later, when Captain Janeway and Q (junior) returned to the Chokuzan ship, the commander revealed himself to be Q, and he was just testing his sons response. (VOY: "Q2")
- It is not stated whether the Chokuzan are a real species or not.