Lullaby Girlfriend is portrayed as a young, mysterious woman. She seems to be calm and collected in almost any situation even in the face of death. Being a demon, she seemingly possesses a great deal of power, but she chooses to hide it.

Lullaby Girlfriend has been confirmed to not be the sharpest tool in the shed, to the point where her faith in Boyfriend is practically blind faith. Her lack of intelligence can result in her getting into difficult situations, she is also shown to be clearly moronic in her mod of origin (Friday Night Funkin' Lullaby) being shown to do rather dorky poses in the songs she's in, she is still capable of making wise decisions and holds her own when facing Hypno.

Lullaby Girlfriend is also shown to be incredibly brave and presumably fearless in the mod, always wearing an unchanged smile, even when Hypno begins to heavily disfigure himself, her boldness remains unchanged. This however, does differ if Hypno's hypnosis manages to affect her as she is shown with a more serious look she becomes partially hypnotized and a dazed exhausted look if she is fully hypnotized.

Appearance She wears a red and white winter beanie, brownish black puffy waist long hair with bangs, black eyes and wears a dark blue mid-sleeve jacket, white fingerless gloves with a small pocket on her left chest, stopping between her wrists. She wears pale blue jeans, along with obviously her dress and red sneakers underneath