Originally created as a friendly AI to aid masters who participatied in the lunar Holy Grail War. Due to a glitch in her coding, she have developed a sadistic tendencies and later took over the Moon's electrical system. She often pretend to aid the players, only to put them in her own trap and mocking them of how powerless they are.
In Fate/Grand Order, she is a MoonCancer-class welfare Servant for the Fate/Extra CCC event.
- BB (Swimsuit Mooncancer) (three distinct outfits: yellow jacket with baseball cap; gyaru with purple bikini and thigh boots; vampire cape with white leotard)