(Kidnapping) Inauspicious Hamelin

Lore
Hamelin fired her gun into the air again, but instead of rats, it was the children of the city that obediently followed her. No force could dissuade them, not even their own parents' pained cries, as they vanished over the horizon and into oblivion...

Acquisition
Evolve 2 Inauspicious Hamelin

Name origin
?

Additional Info
Boss during The Golden Gunshot Odyssey Event.