Uncle's brother was usually called uncle.
Dad's uncle-in-law could be addressed as "uncle","uncle","aunt" or "aunt".
Mother's uncle's daughter was called aunt.
During the Qing years, Fan Xian's uncle was called Wu Zhu.
Well, in the movie 'A Christmas Story', the main character's uncle is named Randy. He is a part of the family and there are various comical situations involving him during the Christmas time.
I'm not sure which specific 'Christmas story' you are referring to. There are many Christmas stories, and each may have different characters. Can you be more specific?
The Fan Xian of Qing Yu Nian was called Wu Zhu.