He's the adopted son of Mario. He wears a diaper outside his pants. When Greg Heffley asked why, he said it was so his pants don't get dirty. Yet he wears it outside so his diaper doesn't get dirty. Mario even says he's a bit of a retard. (S02E10) - Success, But Not A Promise Retrieved from "https://agk-adventures.fandom.com/wiki/Jeffy?oldid=5898" Categories: Characters Season 2 Community content is available under CC-BY-SA unless otherwise noted.