Robomen
The exact nature of the imago, the physical form and appearance of a denizen of the City of the Saved, is subject to various influencing factors. It is rare for a citizen's imago to relate directly to his/her original form. Alterations to the human base form, caused by environmental factors, are frequently carried into the citizen's new life. There is no need of this to be the case; rather, it is a simple matter that the human psyche dictates the imago's form.
To this end, variously altered citizen's are stuck with whatever peculiarities they developed in their original lives. One such group is the Robomen, a faction of the City's inhabitants who manifested with cybernetic attachments to their ur-human bodies. Though not nearly as extensive as many such enhancements (cf Cousin Pinocchio), the attachments are notoriously easy to spot, the Robomen standing out in a crowd due to the enormous silver headphones glued to their craniums.
The Robomen are the result of affiliation/assimilation by a time-active species in the earlier periods of human history. This species had caused a great deal of destruction throughout human history, and had even been known to have engaged the Great Houses. Indeed, speculation is rife that they may, in some way, be linked to the Enemy, though most scholars dismiss this as unlikely. It is possible, however, that several members of this species have been resurrected in the City, due to their biomass having originally been cultivated and/or mutated from human stock. To this end, the Robomen, retaining a residual, desperate urge to serve their extinct masters, have been searching the City's vast area for these legendary creatures.
Fortunately, the Robomen move extremely slowly, and frequently suffer from psychological defects brought on by their conditioning. As yet, they have made no headway, and are very unlikely to pose any kind of a threat. Nevertheless, the Grandfather of House Halfling is said to be interested in their investigations.