Mandragora, also known as the Mandrake, is an extremely tall, lanky humanoid figure. He possesses prominent pointed ears often mistaken for horns and wears thick circular glasses that obscure his eyes, creating an elusive and mysterious aura. His typical attire includes a purple robe and pants with a faint floral pattern over a white button-up shirt. Once sporting long dark purple hair during his time as a rock musician, he now wears his hair short and brown. When angered, he transforms physically: dark scales cover his body, claws emerge on his hands and feet, his clothing shifts to orange and black hues, dark smoke emanates from him, and his eyes emit dangerous sparks.

Originally the pianist for the rock band "Earwig," Mandragora performed at "13 Lime Avenue" alongside Bella Yaga on drums and Earwig's mother as vocalist. The band disbanded for unknown reasons. He subsequently became an author, though his literary works consistently receive poor critical reviews.

He resides with former bandmate Bella Yaga in a magically enhanced cottage. Their relationship is ambiguous and primarily functional. Mandragora enforces strict isolation within the household, demanding not to be disturbed while writing. He exercises significant magical control over the environment, sealing all exits with spells to prevent Earwig's escape and commanding demonic minions who enforce his rules. His volatile temper manifests during disruptions, often triggered by Bella Yaga's criticisms or household chaos, leading to destructive magical outbursts.

Initially an unwilling participant in adopting Earwig, Mandragora showed indifference toward her, merely stating she "should do" when selected. Over time, subtle signs of paternal concern emerged: he reacted positively to her compliments about his cooking, calmed during interactions with her, and intervened on her behalf after a magical confrontation between Earwig and Bella Yaga. During this incident, Earwig redirected Bella Yaga's worm spell into his room, provoking his transformation and rage. After resolving the conflict, he compelled Bella Yaga to grant Earwig's requests for magic lessons and schooling.

By the film's conclusion, Mandragora exhibits softened behavior toward Earwig, using a cutesy nickname for her and personally serving her snacks. His demon minions now follow her commands, indicating a shift in household dynamics where Earwig gains influence. His connection to Earwig's mother and the reasons for the band's dissolution are not revealed.