Greg's Grandpa

Grandpa Heffley is the lovable grandfather of Greg, Rodrick and Manny, and the father of Frank Heffley. His first appearance was in Rodrick Rules, where he offered to let Greg and Rodrick stay at his house; the experience was terrible for Greg. He was seen again in Dog Days, where he finally confessed to Frank at brunch that he ran over his dog, Nutty, enraging Frank. In The Ugly Truth, he appears at his son Gary's wedding, and the family reunion.

Personality and Lifestyle
Grandpa Heffley is strange, unpredictable, and ignorant. He sets his TV only on the CCTV channel, which he enjoys watching, infuriating Greg as he cannot watch "real" television shows at his grandpa's house. He makes a dish called watercress salad, which Greg and Rodrick thinks is disgusting; their grandpa seems to not care. He loves to play a game called Gutbusters as well, and forces Greg to play; Greg always wins because his Grandpa thinks the nonsensical jokes are funny. In Ugly Truth, he is shown to smoke.

Greg Heffley
Greg and Grandpa are on good terms, yet Greg despises his lifestyle. Greg hates the fact that the TV is only on the CCTV channel in which he enjoys watching, infuriating Greg as he cannot watch "real" television shows at his grandpa's house. Also, he makes a watercress salad, which Greg hates and forces Greg to play very old games, which Greg always wins since Greg does not get any of the jokes properly. According to him, Greg is his favorite grandson.

Frank Heffley
Frank and Grandpa had a distant relationship, until Dog Days, where they now both have a very tense relationship. This is largely because when Grandpa confessed that he killed Nutty, while trying to park the car, in which Grandpa thought was Frank's skateboard, thus enraging Frank, and ending with a tense relationship. In the online book, Frank over-reacts to this more that the locks Grandpa out of the house.

Uncle Joe
Unlike Frank, there is clearly no existent relation with his other son, Joe.