Mordo was a place in the Spaceman Spiff universe. Possibly a planet, Mordo was where the Muck Monsters came from. "It'll build character!" This article is a stub. You can help the The Calvin and Hobbes Wiki by expanding it. Retrieved from "https://calvinandhobbes.fandom.com/wiki/Mordo?oldid=28208" Categories: Article stubs Spaceman Spiff universe places Spaceman Spiff universe planets Planets Unseen places Spaceman Spiff universe Places in Calvin's imagination Community content is available under CC-BY-SA unless otherwise noted.