Dark Heresy: The Corruption Within
Grox are large (5 meters long), fast and aggressive reptilian animal. Originally from the Solomon System, the grox are now found throughout the Imperium. Usually contained to agri-worlds, grox can survive on near anything and exist in almost any environment. Their meat is considered quite palatable and is highly nutritious. They are the most common livestock in the Imperium.
They are, however, exceedingly aggressive. Grox will attack any creature that comes within their sight, other grox included. Very territorial, herding grox is a task only possible thanks to the lobotomies that all grox except for breeding stock go through. Those kept for breeding are kept under some control using electrical implants within their small brains. Even so, accidents will happen.
- Source: Warhammer 40,000: Rogue Trader (1987), pp. 212-213
- Source: Warhammer 40k Wiki