Catachan is the most infamous Imperial Death World in the galaxy. It is located in the Ultima Segmentum and is covered in dense jungle. The planet's entire ecosystem seems consciously hostile to all foreign life. Each and every element of the native flora and fauna of the planet represents a real danger to any human. Catachan's only valuable resource is its people, who by virtue of being born on the harshest world in the Imperium are invariably tough and cunning. It is home to the renowned Catachan Jungle Fighters regiments of the Imperial Guard.
Catachan was colonised by humans millennia ago during the Dark Age of Technology, long before the Imperium of Man was established. When the first exploratory probes arrived in its star system, the planet was a deceptive, calm green orb when scrutinized from orbit, but when the first colony ships crash-landed on the jungle planet and the colonists had no way to escape, they discovered themselves to have arrived on one of the harshest and most dangerous planetary ecosystems in the galaxy. The colonists only barely survived, holed up in their spacecraft against a living, besieging jungle, a battle for survival in which undoubtedly many of them died before they finally managed to learn enough about their new homeworld to survive, if not thrive, beneath its jungle canopies. In time, their skill at surviving on Catachan came to the notice of the Departmento Munitorum, which realised that the Catachans would make excellent Imperial Guard troops dedicated to service in some of the galaxy's most hostile planetary environments, and the first regiments of the Catachan Jungle Fighters were raised.
Currently, the few human settlements on Catachan which can defend against the jungle forces are giant fortresses surrounded by vast plains which have been laboriously cleared to provide improved lines-of-fire. Building on Catachan is difficult at best as vines and lichen take hold anywhere and poisons melt the mortar and vines can crush bunkers and tanks. Buildings must constantly be rebuilt, it seems that wherever they build the jungle redoubles its efforts to destroy them. As well as the jungle, the native wildlife gather to repel the human invaders and eventually their numbers grow large enough to push the humans out of their settlement so they must find another settlement elsewhere where the process will inevitably repeat itself, meaning that no human settlement on Catachan is ever truly permanent. In such dangerous surroundings, children are quick to learn survival tactics and only those who are fast and have good aim survive to adulthood. The children of Catachan often learn to shoot before they walk, much like Cadian children.
Flora and Fauna of Catachan
All of the animals and plants of Catachan are deadly predators who have evolved potent biological attack and defense mechanisms against other lifeforms, particularly humans. Every known Catachan plant species is toxic, making foraging for native food impossible. Some plants secrete pollen into the air which is poisonous and destroys air-filters. Others secrete sticky liquid to capture passing animals and slowly dissolve them, much like giant Venus Fly-Traps. Other plants poison the ground and turn the immediate area around them into boggy wasteland to trap invaders. The native animals are as deadly to humanity as the plant life. for instance, the massive insectoid predator called the Catachan Devil possesses jaws as big as a tank and is a major threat to human population centres on the world. The Shambling Mamorphs of the volcanic regions are also a great danger to human settlement.
- The Brainleaf, a vegetative carnivore, is a small tree, not particularly conspicuous on Catachan, but is able to attach its tendrils to the spine and brain of any animal, taking control over their body. This creature may actually be a genetic offshoot of the Tyranid Cortex Leech, a creature with similar abilities, that was cut off from the Hive Mind and went feral.
- The Spiker, another deadly plant, fires its spikes into its victims' bodies, which contain the Spiker's DNA and unleash a series of mutative chemical reactions which literally transforms the person into another Spiker.
- The Venus Mantrap is a carnivorous plant whose analogous species are common to many jungle Deathworlds across the galaxy. It resembles the Terran Venus Flytrap for which it is named, but is far larger, and unlike the flytrap, it is not stationary but is able to move its leaves to attack and consume its prey. The Mantrap consists of a number of mobile leaves attached to a single immobile stem.
- One of the most famous deadly animals of Catachan is the Catachan Devil, a voracious insectoid predator, looking somewhat like a many-limbed Terran scorpion or centipede. They can be as long as a land train but are very bulky and slow-moving, which means that escape is possible for the unlucky humans who confront one.
- The great quadrupeds called Grox, although originally native to the Soloman System, are also found on Catachan, perhaps brought by the early human colonists. The animals are prized for their highly nutritious and tasty meat, and have been introduced to many worlds throughout the galaxy, so that the Grox is now the most ubiquitous livestock animal in the Imperium. The Grox however are extremely ornery and virtually impossible to keep under control without some form of brain-implants or lobotomy - on Catachan they have become wild, and are deadly predators. Grox are used by a galaxy-spanning food consortium to produce the famous 'Grox Burgers'.
- The Shambling Mamorphs of the volcano lands are tough fighters and put up a good fight even against the Catachan Devil.
- There are also many types of reptiloid serpents on Catachan, including the Flying Swamp Mamba, the Coiling Death Cobra and the Catachan Black Viper, and all are deadly to most living beings. Some have toxin that is so powerful it can kill in under 30 heartbeats.
- Great Barking Toads, although appearing benign and harmless, are literally volatile creatures: the creature is easily startled, and anything it finds threatening is liable to cause it to explode in a cloud of toxins which kills anything within a very wide (one-kilometer) area, including the Barking Toad itself. The Barking Toad toxin is virulent enough that even respirators and sealed suits such as power armour offer no protection. They are known as the most toxic creatures in the galaxy.
- Codex: Imperial Guard (2nd Edition)
- Warhammer 40,000 3rd Edition Rulebook
- Warhammer 40,000: Rogue Trader (1st Edition)
- Codex: Imperial Guard (5th Edition)
- Warhammer 40,000 Chapter Approved - The Book of the Astronomican, Introduction