Leonie Rykermann was the wife of Nils Rykermann and a notable figure in the resistance against the Kzin Occupation as well as the post war reconciliation period. A former student of Nils, Leonie competed with Dimity Carmody or the professor's attention. After Dimity's apparent death at the hands of the Kzin, Nils and Leonie were married. Although Nils loved his wife very much, affectionately referring to her as "lion-cub," he harbored a secret love for Dimity throughout most of their marriage. Through Leonie became a friend and mentor to Vaemar-Riit, alonside Dimity and Nils, and helped him in his education and pursuit of a unified and evolved Kzin culture on Wunderland
Leonie and Nils, along with Raargh-Hero survived a fierce battle with the Morlocks inside of Wunderlands caves in 2408 C.E. This incident formed an unbreakable bond between the three, which remained in place even after the conflict ended. Leonie would later be seriously injured in another battle in 2428 C.E., this time while fighting a renegade faction of Kzin led by Henrietta who were seeking to re-ignite a full scale conflict between man and Kzin on Wunderland. During the course of the battle, the human traitor Jocelyn Van Der Strat turned her laser on Leonie, nearly cutting her in two at the waist. Only the intervention of Vaemar Riit and the application of first aide by Dimity saved her life. Her lower half would later be replaced with those of a donor, marking a distinct change in her physical appearance.