The Grox is a large, fast and aggressive reptilian animal originating from the Solomon System. When that star system was absorbed into the Imperium, it was discovered the animal possessed many useful traits, such as the ability to survive in almost any planetary environment and the omnivorous ability to thrive on even the most indigestible food.
Grox meat itself is also extremely palatable and nutritious, and nearly every single part of the beast is edible. Because of their value as livestock they have since been introduced to other worlds throughout the entire galaxy, so that the Grox is now the most common type of livestock animal throughout the Imperium.
The only drawback to the Grox is their aggressive and vicious temperament. They will usually charge any creature in sight, including other Grox. They are also large, fast, and dangerous beasts, about five metres long and well-muscled.
They are territorial and like their privacy, so attempting to herd Grox together would easily drive them into a rage. The solution used is to lobotomise most of the stock while keeping the breeding animals suppressed with electro-pulsers wired directly into their small brains. Even with these precautions, accidents still happen, and Grox are usually kept on Agri-worlds and isolated from human settlements.
Grox are used by a galaxy-spanning Imperial food consortium to produce the famous "Grox Burgers." This consortium issues charters to Rogue Traders who are in turn given carte blanche over creating franchises and Grox farms.
The Argrax is an even more temperamental herd reptile from the world of Aurum, which is recognised as a cousin of the ubiquitous Grox.
- Warhammer 40,000: Rogue Trader (1st Edition) (1987), pp. 212-213
- Deathwatch - The Emperor Protects (RPG), pg. 46