TV-Series
Description
Ratten emerged from Rattenfänger, a community formed by the 130 children lost in the Hamelin legend. Unlike the myth of a piper leading them away, these children succumbed to natural disasters and later forged a bond with a fairy. They utilized stone from Seikairyuuou to construct the golem Deen. Ratten embodies one facet of the Pied Piper of Hamelin legend, specifically representing the piper who commanded rats. Summoned with fellow demons Weser and Strum by the Ouroboros Alliance, she entered the service of the Demon Lord Black Percher and co-founded the community Grimm Grimoire Hamelin.

Physically, Ratten presents as a young woman with fair skin, blue eyes, elf-like ears, and short blonde hair. Her attire is distinctively white: a pointy hat, cape, undergarments, puffy leg warmers, and heeled shoes, accented with purple linings. She is seldom without her signature silver flute.

Her personality blends mischievousness, pride, and fierce loyalty. She exhibits masochistic tendencies, interpreting Percher’s threats as praise, and feels palpable jealousy when Percher grants Weser the gift of Divinity. Despite her sadistic enjoyment of manipulating victims into fighting comrades or commanding rats to attack, she honors her commitments. This is starkly evident in her final battle against Kudou Asuka, where she fights earnestly despite foreseeing defeat and accepts death with dignity.

Ratten’s primary ability channels through her flute, using hypnotic melodies to manipulate minds and command rats. A few notes can fully dominate ordinary humans, though resilient opponents like the No Name community members suffer only paralysis or pain. She also possesses self-sustained flight. Her combat strategy prioritizes manipulation over direct confrontation, leveraging controlled minions whenever possible.

Her key relationships define her motivations. She collaborates effectively with Weser despite finding him occasionally irritating. Her absolute devotion to Black Percher stems from Percher adopting the Grimm Grimoire name for the community; Ratten pledges eternal allegiance and requests a final farewell to Percher as she dies. Her dynamic with Kudou Asuka evolves from viewing her as a plaything to respecting her as a worthy opponent. During negotiations, Ratten demands Asuka’s inclusion in their community, later confronting her in a decisive Gift Game.

Her involvement spans critical events:
- She first attacks Asuka’s group indirectly by manipulating rats, thwarted by Leticia Draculea.
- During the Salamandra festival assault, she mind-controls soldiers to instigate infighting and engages Asuka’s group directly. Though she overpowers Asuka temporarily, the intervention of a Judge Master halts the conflict.
- In the resumed Gift Game, she commands the Strums against Asuka and Deen. After Deen crushes her in retaliation, Asuka offers a challenge: if Ratten seizes control of Deen, Asuka surrenders. Ratten fails, accepting loss gracefully. In her final moments, she expresses gratitude for the duel and requests Asuka relay her farewell to Percher.

Her character arc concludes with this battle, emphasizing her unwavering loyalty to Percher and her community even in defeat.