Jägermonster

A Jägermonster (usually just Jäger) is a construct created by a Spark, usually as a part of the Spark's military forces. Jägers have a broadly humanoid appearance, although in general they're rather ... odd ... looking and unlikely to be confused with real live humans. They are created by some Spark-ish process that hasn't been fully described yet, but apparently involves consumption of some infernal potion.

Jägers are feared by many humans, for several reasons. For starters, they're fearsome hand-to-hand fighters (the name, after all, translates roughly as "fighter monster") who can absorb extraordinary amounts of damage and still not only function but bloodily slay those responsible for the damage. For another, they're historically associated with some of the truly infamous Sparks (most recently Baron Klaus Wulfenbach) who send them out on missions, most of them involving serious carnage. And of course, there's the entire Frankenstein-monster mystique.

Jägers in the story tend to speak with a German-like accent, which seems reasonable enough.