"Mr. Von Braun" would be presumed to be the former name of the otherwise unidentified father of Emmett L. Brown, as well as other paternal ancestors.
Behind the scenes
However, no mention of Mr. Brown or Mr. Von Braun is made in the materials associated with Back to the Future, including the only animated series episode describing Emmett's childhood, "Gone Fishin'".
Appearances
- Back to the Future Part III (Inferred to)