Kyubey (aka Incubator) is the familiar from Puella Magi Madoka Magica. He enlists the help of young girls to battle witches in exchange for a wish.Like any other magic girl familiar, he is on a mission to save the “universe.” He shows up conveniently to enlist a young girl on the verge of wanting or wishing something.
Despite already having enlisted many girls to become Puella Magi, he is constantly trying to enlist Madoka, the main protagonist, to become one because he claims that she posses great magical potential in her. His efforts are frequently thwarted by another Puella Magi named Homura Akemi.
Deceptively cute and helpful, he lacks emotion and empathy towards the enlisted magic girls unlike your usual fare of magic girl familiars. He is actually an alien posing as a familiar. His true name is Incubator, whose true purpose is to raise Puella Magi so that they may eventually become witches. His “race” use the energy generated from the transformation to counter entropy and prevent the impending heat death of the universe. He claims his lack emotion and understanding of human values are not cruel but utilitarian in nature. He has an unknown number of bodies; when one is killed, another simply appears near the destroyed one eating it.