Barry Sonnenfeld:
the passenger on the model train that a giant Gomez looks into the window and laughs at before the two model trains crash into each other.
Near the end of the movie when the family is playing the "Wake the Dead" game in the family cemetery one headstone in the foreground says Ansel Addams - a clear reference to the famous photographer Ansel Adams.
After Fester first arrives, the "stormy night" scene shows a fence and large tree or long drain pipe in front of the Addams mansion, yet in the "next morning" daylight shot, both are gone.
Grandmamma is seeing performing during the Mamushka, and also walking by Tully and the doctor while the Mamushka is being performed. One of the dancers with a dark hat who's performing the Mamushka is seen to the right as Tully leaves. Also, Margaret and Cousin It are seen walking past them while at the same time watching the dance.