Tesla, Technographer Jak Tesla. It sounds as though it ought to belong to a rakish young man with unshaven stubble in a sleeveless black leather waistcoat, a heavy hellpistol riding low on one hip and a barely-dressed female assassin hanging off the other.

 The universe doesn't have the same sense of narrative necessity as humanity however, so as misfortune would have it what the universe actually gets is somewhere around seven feet of gangling cerametal and flesh draped in crimson ceremonial robes that mainly expose the gleam of unexpectedly cheerful occular implants set over a rebreather that's shaped in the aquiline fashion of the Imperial Eagle, a short and curving brass beak under which is the grill-like expanse of a streamlined (and rather stylish) voder system that gives him a deep and resonant voice capable of filling a room at will while his gait is inhumanly, smoothly polished in a way that speaks eloquently of augmetic rather than natural legs beneath his robes - or possibly just affectation, you all know what the Cogboys are like.

 He usually carries an Adeptus staff as a badge of office, graven with minuscule sigils and binary incantations, while in time of conflict he often bears an ornately worked manifestation of the Will of Man in the form of a Bolt Gun, much engraved with tiny icons of technological supremacy.