Leopolda Stain was a warlock from Vienna.
Sometime before 1878, Leopolda met Axel Mortmain and shared his ideas about the destruction of Shadowhunters, which later led her to travel from her home in Vienna to London, in 1901, with the intention of obtaining Nephilim blood. Leopolda was also a friend of Malcolm Fade, and went to the London Shadow Market during her visit to bring him a book that he had asked for; It was there that she met Brother Zachariah, another friend of Malcolm.
Shortly after, Leopolda was at a meeting of mundanes and Downworlders in Soho, where she met Matthew Fairchild and Anna Lightwood, whom she took an interest in. A week later, Leopolda helped a few mundanes to invoke a group of demons, who then murdered several of those present; actions that were witnessed by Anna and Ariadne Bridgestock.
During the attack, Leopolda was stopped by Brother Zachariah, to whom she offered to tell the identity of the biological father of Tessa Gray in exchange for some of his blood, to which he refused. After the two began fighting again, Leopolda managed to escape, but was then caught by werewolves under Woolsey Scott leadership, who contained her until Brother Zachariah showed up again. The two chatted and Leopolda revealed some of her information to him, before asking for his blood in exchange for more. When he refused again, Leopolda tried to leave once more but was stopped by the werewolves, who were waiting outside the door during her conversation with Brother Zachariah. The werewolves murdered her for breaking the Accords.
Leopolda had a scaled skin of a snake, colored silver, and long green hair.
- Immortality: As a warlock, Leopolda was immortal and did not physically age.
- Magic: As a warlock, Leopolda could use magic.
- Every Exquisite Thing (first and only appearance)