Mister Boobrie is a small, bird-like creature who serves as the constant companion of the sorceress Mélie. Its appearance is notable for lime-green skin, a beak, bat-like wings, and two small, beige-tinted ram horns that curl twice. Despite its diminutive size, it possesses surprising physical strength, enough to carry the weight of an average-sized teenager during flight, as seen when it transports both Mélie and Seth. It is most often found perched within Mélie's voluminous hair or riding on top of it.

The creature’s personality is closely tied to Mélie’s emotional state and her unique split-personality condition. When Mélie is in her gentle, cheerful, and happy-go-lucky default state, Mister Boobrie tends to be volatile, aggressive, and unforgiving. It reacts harshly to what it perceives as slights or annoyances, frequently pecking or biting Mélie, especially during moments of joy or celebration. In this mode, it is fearless and quick to confront perceived threats, even driving away animals much larger than itself, such as cats. However, when Mélie’s aggressive, battle-ready personality emerges under stress or danger, Mister Boobrie’s demeanor flips dramatically. In this state, it becomes masochistic, apparently deriving enjoyment from the rough treatment it receives from Mélie’s fiercer side. This contrast in behavior makes it a mirror of her internal conflict.

Mister Boobrie’s role in the story is primarily as Mélie’s closest and most loyal companion. It follows her everywhere and acts as a constant presence in her life, providing both transport and a unique form of emotional support. Its motivations are simple: it remains devoted to Mélie, and its actions are driven by its attachment to her, particularly enjoying the intensity of her aggressive personality. In terms of key relationships, its bond with Mélie is central, and it shows little direct interaction with other characters beyond occasional conflicts or carrying them.

The character experiences little visible development throughout the anime, remaining consistent in its dual nature. Its abilities are limited but effective: sustained flight, the strength to carry passengers, and a sharp beak used for pecking. These traits make it a useful, if irritable, ally. Mister Boobrie’s unusual temperament and deep connection to Mélie’s fractured psyche make it a memorable and distinctive presence in the series.