The Mandrake presents an unnervingly tall and lanky figure, distinguished by pointed ears often mistaken for horns and thick circular glasses that obscure his expressions. He typically sports a purple robe with a faint floral pattern over a white button-up shirt. This appearance shatters when anger takes hold: dark scales erupt across his skin, claws extend, and dark smoke billows from his body. His clothing shifts to orange and black tones while his eyes ignite with intensity.

Formerly the pianist for the rock band Earwig, he later pursued an unsuccessful career as an author. He now shares a residence with another former band member, Bella Yaga, their relationship defined by ambiguous and cynical coexistence rather than friendship. His adoption of Erica (later named Earwig) stemmed solely from Bella Yaga's need for household labor; he displayed initial indifference to the selection.

Within the household, he reigns at the apex of a strict hierarchy, commanding fear through his immense magical power and volatile temper. He demands undisturbed solitude for writing, magically sealing all exits to enforce isolation. His fury manifests physically: veins protrude on his forehead, smoke billows from his back, and he summons bat-winged demonic minions to enforce his will. Despite this fearsome volatility, rare moments of softness emerge, such as calming when Erica compliments his cooking, eventually developing a distant affection for her.

His potent magic extends beyond confinement to manipulating the very architecture of the house, creating or removing doors at will. When pushed to extremes, he partially transforms into a scaled, fiery entity capable of breaching walls. Though initially aloof towards Erica, subtle signs of care appear; he eventually permits her to attend school and gifts her snacks. He also reveals a cryptic connection between magic and music, hinting at his past, while pointedly avoiding elaboration on Erica's mother or the band's history.