Catachan is the most infamous and lethal Death World in the entire galaxy. It was colonized by humans longer than Imperial records can remember. When the first probes arrived, the planet was a deceptive, calm green orb from orbit but when the colony ships crash-landed and the colonists had no way to escape, they awoke to find themselves on one of the harshest planets in the galaxy. The colonists only barely survived, holed up in their spacecraft against a living, besieging jungle, a battle for survival in which many undoubtedly died.
 
The people of Catachan are not only hardy, but pragmatic, with an easy grasp of realities and an uncomplicated attitude towards danger. They are also somewhat disdainful towards people from other worlds, believing - with good reason - that few others in the galaxy have had an upbringing as dangerous as their own. Catachans are known for being both physically and mentally resilient on a level that normal humans simply cannot match. Due to their heavily muscled physiques, they are often nicknamed "Baby Ogryns" by other Guardsmen, although never to their faces, as it often results in serious injury.