The Hirogen were a nomadic species of hunters who were encountered by the USS Voyager in the Delta Quadrant. They viewed other lifeforms as prey and treated them as such, showing little evidence of morality.
Hirogen adult males were quite large, standing above the average height of other known humanoid species. They also possessed greater physical strength than most humanoids afforded to them by their advanced muscle and nervous system. Their sensory perception was acute, a feature that served well as the Hirogen were an aggressive hunting species. The Hirogen also possessed an impressive immune system and used an enzyme to break down the bones and muscle tissue of their prey, suggesting that the Hirogen used some of their victims as food. The color of Hirogen blood was red.
Little is known about Hirogen women, though it has been suggested that they pursued male hunters in possession of rare or unique trophies acquired during a hunt.