The Space Wolves do not dwell alone in the mighty fortress, The Fang. Like all Space Marine chapters, they are too few in number to maintain such a massive organization. There are numerous tasks that must be performed just to maintain The Fang: continual updating of its material fabric and weaponry, and the monitoring of its power grid and the thermal wells that draw heat from deep beneath the surface of Fenris. Like other Space Marine Chapters, the Space Wolves maintain a large fleet ever ready for war, and The Fang includes huge dockyards and all the facilities needed to equip and control the fleets. There are countless other things which must be done just to preserve the chapter in its continual state of readiness. It is hardly surprising that The Fang is home to a large population of the chapter's Bondi. There are many more Bondi who live outside The Fang on the island of Asaheim, and in far-flung outposts across the world of Fenris.
The chapter's Bondi are loyal members of the Chapter and followers of the Wolf Cult, although they are not Space Wolves. The ancestors of these warrior-retainers came to The Fang and to the service of the Space Wolves many thousands of years ago. Some are descended from Fenrisian warriors who may have been selected as potential Space Wolves, but who were judged incapable of enduring the final testing. Such individuals are brought to The Fang to serve their masters in a more humble but equally vital capacity.
Every Great Company has its own Bondi, and the Great Wolf himself has the largest number of these of all the Wolf Lords. Most of the spacecraft crews, drivers, and the warriors who man Fenris's defenses are Bondi. When the chapter goes to war, it is these Bondi who keep The Fang running and defend Fenris against attack.