Nega Cat is a key supporting character in the anime series 'Mahou no Tenshi Creamy Mami.' Nega is a magical, talking cat who, alongside his companion Posi, guides the protagonist, Yuu Morisawa, after she becomes the magical girl Creamy Mami. Nega serves as a mentor and advisor, offering advice and sometimes comic relief. His mysterious and sometimes mischievous personality adds depth to the magical world, and his guidance is crucial to Yuu's transformation and her adventures as Creamy Mami.