Geisterdragon

This weird beast never gets an official name in the story, but since it's affiliated with the Geisterdamen, "Geisterdragon" seems reasonable. It first appears here, helping a pair of Geisterdamen stand guard in Sturmhalten just as a swarm of flying Dingbots created by Agatha breaks out to send the message that she's in need of a rescue. It notices, and busily sets to work destroying the Dingbots, but one gets through to spread the word. Just about this time, Ardsley Wooster shows up in Gil's rebuilt  flying machine, which also catches the Geisterdragon's attention, but a nice bit of subterfuge by the surviving Dingbot sends it careening to what appears to be its doom, and on the Dingbot goes to do its thing.

It's unclear whether this critter is a Construct or something natural -- "natural" being something of a relative term, to be sure, and if it is "natural," it's only thus on the Geisterdamen's home plane of existence (whatever that is), not the one with Europa and the rest of the Foglio-verse. It's certainly clear enough, however, that you don't really want to run into another one like it, so it's categorized among the Villains for now.