There are two people called "uncles" by the locals, both of whom are in the entertainment circle. One is Li Jianren, who was named after playing "Uncle" in 1999' s "Three Sides". Another more famous "Uncle" is the late actor Ng Man Tat, who is widely known for playing "Uncle" in several gambling saints series.
As far as writers are concerned, there are famous "four gifted scholars in rural areas and Hong Kong", one of whom is the late songwriter James J.S.Wong, known as "Uncle Zhan".