Great-Great-Uncle Bruce
Name Bruce
Age 87 (at time of death)
Gender Male
Actor None
Film Appearance? No
Online Appearance? No
Book Appearance? Yes

Bruce was Greg Heffley's great-great-uncle, who passed away some years prior to the start of "Cabin Fever".  Greg mentions him in an anecdote about the hand-knit blanket Bruce used in the hospital; the blanket had been passed off to Greg after his death. Greg immediately stopped using it after viewing a photograph of Bruce wearing the blanket, and pawned it off to his brother Rodrick on his birthday. He was later mentioned in "The Third Wheel" at the dance. Greg had put on his cologne, thinking it was safer than Rodrick's body spray. However, he regretted that later on because Bruce's deodorant attracted the old ladies who attended the dance after the meeting.

Great-Great-Uncle Bruce is the brother of Gammie Heffley and the grandfather of Terrence Heffley. In the books he is called Great Uncle Bruce possibly because he is Dad's great uncle.