Joe Heffley

Joe Heffley is the younger brother and rival of Frank Heffley, brother-in-law of Susan Heffley, and uncle of our protaganist, Rodrick Heffley and Manny Heffley

Role in Diary of a Wimpy Kid: Rodrick Rules
Joe comes to Greg's house late for Thankgiving. His children all call their uncle "Aunt Fwank (Frank)." Susan says that this is cute but Frank says that Joe taught them to do that. When Frank goes down to the basement to do edits to his Civil War diorama, Joe sneaks down and says "Nice toys, big brother!" Frank explains everything to Joe, but Joe didn't listen to a syllable he was saying. Greg mentions that the year before that book takes place, Manny was appr. 2 weeks from geetting out of diapers, but Joe puts a stop to it by saying "Watch out for the 'potty monster,' little fella!" Everytime time Frank had to change a dirty diaper after that, he swore under Joe's name.

Role in Diary of a Wimpy Kid: Dog Days
Greg says he asks Joe to encourage Frank to buy a dog. Joe slaps Frank's back saying "A boy needs a dog!" Later he is at Greg's birthday partyand his dog Killer eats some of Greg's birthday cake.