Spider Zero is the mutation of the experimental Artificial Intelligence "Zero", created by Hitoshi Kobe's father, inadvertently cross-bred with a Spider virus by Yayoi Kobe who used the completed Reality Module of Forty Namba to bring Zero to life.
Zero's character design would later influence the visual design of Negima! Magister Negi Magi's antagonist Fate Averruncus and the Averruncus golem series as well as an as-of-yet-named character in UQ Holder!.
- The core programming of Saati Namba, Toeni Namba and Forty Namba are all based off of Zero's core programming.
- Spider Zero gained physical form at around 1:00 am.
- When Zero and Saati's fight became televised across Japan, a child claimed that Zero was Sephiroth from the Final Fantasy videogame series.