Grandfather is the main antagonist of Codename: Kids Next Door – Operation: Z.E.R.O.. He is reawaken by his Son after his Numbuh 0 defeated him. Sorry, Doc, but this Article is Under Construction This article or section is under construction/expansion. Please help us work on it. Retrieved from "https://warnerbros.fandom.com/wiki/Grandfather_(Codename:_Kids_Next_Door)?oldid=46123" Categories: Pages under construction Community content is available under CC-BY-SA unless otherwise noted.