- Kyubey (キュゥべえ Kyūbē?)
- Voiced by: Emiri Katō (Japanese), Cassandra Lee (English)
- Kyubey is a genderless (though he apparently identifies as a male) extraterrestrial being posing as a familiar
who can grant any wish to a certain girl, on the condition that she become a magical girl and fight against witches. When the chosen girl makes a contract with him, he extracts her soul and places it inside a soul gem, reconstructing their body into a shell that is more resilient in order to fight witches. He constantly tries to get Madoka to make a contract with him, as she allegedly possesses great magical potential within her that would allow her to become the most powerful magical girl. He can only be seen or heard by magical girls and those with "magical" potential, and is able to communicate with them telepathically. Kyubey has an unknown but possibly infinite number of bodies; when one is killed, another body appears and devours the destroyed body.
- Kyubey comes from a race named the Incubators (インキュベーター Inkyubētā?), whose goal is to find and gather a form of energy to counter entropy and prevent the impending heat death of the universe,
developing a technology to turn emotions into this energy. After evaluating many species throughout the universe, the Incubators find that the souls of humans, specifically pubescent and prepubescent girls, contain the most powerful form of this energy. This energy is the strongest when a magical girl's soul gem turns into a grief seed, and then can be collected and used towards preventing entropy. Kyubey claims his race lacks emotions (or, at least, that those in his race who have emotions are abnormal), and has little understanding of human values and morality, not understanding why the death of one human among billions is viewed so catastrophically, instead believing the Incubators' actions are not cruel but utilitarian in nature. Despite this, Kyubey is a very skilled manipulator, never actually lying, but instead leaving out important details involved in the forming of contracts and the details behind them, only presenting the truth when it is asked of him. According to Kyubey, the very existence of the Magi-Witch system is what allowed the evolution of mankind's civilization, as many of the main events in human history have had magical girls involved. Despite answering all questions posed to him, there is still much about the universe that Kyubey has not spoken of.
- In Puella Magi Kazumi Magica, Kyubey also appears as the
contractor of all the magical girls in Asanaru City, including the Pleiades Saints. When the Pleiades learnt the truth about magical girls, they took one of Kyubey's corpses and manufactured their own Incubator named Jubey, who could absorb darkness from soul gems. Furthermore, they had Umika cast a spell that would make Kyubey invisible to all other girls in the city and rewrite their own memories to believe they contracted with Jubey, in an attempt to stop more witches from being born. This ultimately backfires as Jubey turns out to be a failure.
- Rebellion shows that the Incubators are a hive mind race. In
the events of the movie, the Incubators tried to control Ultimate Madoka and the Law of Cycles in order to restore the witch system of previous timelines, since more energy could be harvested via the old system. However, their plan was thwarted and Homura ended up stealing Ultimate Madoka's powers for herself, enslaving their race and using them to take on the curses of the new world in place of Madoka. Kyubey is last seen laying on the ground, disheveled and shivering as he is driven mad by his sudden ability to feel emotions combined with being forced to shoulder the combined grief, suffering, and despair of every magical girl that is, was, or ever will be.
Kyubey also appeared in the project-in-the-making series The Plushy Movie. Kyubey is shown to be now the good guy in the series, although letting the heroes make their own decisions of their lives. Kyubey has been taken to the 2nd Quarter Quell by President Snow. Kyubey's not the only one in the 50th Hunger Games. There's Dory from Finding Nemo, Joy from Napping Princess, Tenma Tsukamoto in School Rumble, Karara from Sgt. Frog, Ponyo from Ponyo, Duck from Princess Tutu, Katy from Katy Caterpillar and Yotsuba Koiwai from Yotsuba&! Kyubey doesn't appreciate President Snow for taking him in the Hunger Games. He also appears in the LittleBigPlanet series in the Marvel Cinematic Universe, a superhero thriller anime Girl Force, which he's the leader of the Girl Force, and a playable character in both Plushy Dimensions Year 3 and Plushy Battle Royale 2.