Joe Heffley

Uncle Joe or Joe Heffley is the younger brother and rival of Frank Heffley, brother-in-law of Susan Heffley, and uncle of our protagonist, Rodrick Heffley and Manny Heffley and a minor antagonist in the series.

Personality
Uncle Joe is evidently the most troublesome character in the series, who inadvernteley embarasses, harms and wreck's Frank's Family, by causing lots of pain and disgust.

Trivia

 * Even though Uncle Joe is younger than Frank, the illustration of his moustache and other features may imply that Uncle Joe is older than what Greg's portrays him to be.