Mujika is a significant character in the anime series "The Promised Neverland." She is a demon who possesses the ability to nullify the effects of the demon's desire for human flesh by producing a special kind of blood. This ability challenges the societal norms and beliefs of the demons in the series, as she offers a different perspective on coexistence between humans and demons. Mujika represents hope, empathy, and the possibility of peace between different species in the story.