Ork invasions are devastating to the hapless planets they descend upon. When the Waaagh! finally leaves the battle-scarred planet in search of fresh conquest, the survivors emerge from hiding and the process of rebuilding must begin. Unfortunately for the planet's inhabitants the Ork threat does not end when the vast hulks leave the system. A small trace of the Ork Waaagh! is left behind and will in time grow into a new menace known as Feral Orks.

All Orks give off spores which are dispersed on the wind. A few of these spores may fall into remote zones on a planet's surface, the dense jungles or dry arid plains, places where most civilisation finds it difficult to survive. The spores rapidly infest the area and grow without the threat of discovery. Over a relatively short period of time, these spores will mature into full-grown Orks and band together in loose tribes.

At first these tribes are small in number and are of little threat to the planet's inhabitants. The Orks are uncivilised, even by the low standards of Orks. They have little concept of language and no grasp of technology. At this early stage in their existence they are hunted and preyed upon by all manner of savage beasts. It is a very important stage in the Feral Orks' development, where only the strongest will survive.

Out of this period a particularly cunning and strong Ork will emerge as the leader and the other Orks will gather round him. It is at this point that a Feral Ork tribe will begin to emerge. The tribe learns to fight against their natural predators through use of its numbers and, as it grows and expands its territory, more and more Orks are drawn to the group.

The Feral Orks learn to scavenge weapons and equipment left by the previous Waaagh! Although much of the technology is far too advanced for them, it does not take long for the Ork to realise the gruesome effect of pointing the noisy metal thing at an enemy. Minutes after this incredible discovery the tribe will go to war, shooting at any targets that come before them, conquering all the other rival tribes and uniting under one banner.

The tribes usually take the name of the deadly beast that posed them the greatest threat before they became kultured. As more and more Orks join the tribe they are able to specialise in their abilities. The biggest and strongest Orks are able to bully the smaller and newer members of the tribe to hunt down prey. They take the approach that the bigger you are, the more you need to eat and, therefore, the bigger your portion of the kill. Few Orks dare argue with that kind of logic.

As the smaller Orks spend much of their time hunting down prey, they become excellent shots. Others learn how to track and trap their prey, taking the skulls or hides as trophies of their prowess. Some learn to make use of the beasts of their home world using them as mounts to hunt down fast prey. Some will discover other primitive tribes, and so the main tribe grows exponentially.

As the tribe expands, claiming more and more territory, it is inevitable that it will clash with other races. At first only small outposts will be attacked. Then the tribes will strike in massive raids against towns and entire cities, before swiftly disappearing back into the wilderness. With each new raid the tribe gains more and more equipment and more and more thirst for battle until it will launch itself on a frenzy of conquest.

Once the Feral Ork Waaagh! has started, it can gain an unstoppable momentum. The entire planet will become consumed by the Orks in a furore of battle, until all that there remains to fight is each other, which they do with savage abandon.