|The following is based on Fallout Tactics cut content and is not canon.|
The wild plains were once home for Fleetfoot, where he would run with the rabid dogs. Fast and quiet, he has since learnt to apply the same skills to battle. He works best on his own.
According to campaign description file, Fleetfoot and Slicer were supposed to be available for recruiting after the Rock Falls mission as a reward for completing some optional objective (possibly rescuing Nanuk). But due to some unknown reason they have never made it into the recruiting pool.
Fleetfoot was supposed to appear in Fallout Tactics but never made it, either due to being cut form the final game or due to a bug.