While he hasn't been in many movies and TV shows, he did have some roles in:
* The Godfather Part III (1990): He played the role of "Young Don Vito Corleone." This was his most prominent film role.
* The Gambler (1974): He had a small part in this film starring James Caan.
He also had a recurring role in the TV series "The Equalizer" (1985-1989), playing the character "Angelo."
Beyond these, he primarily has a very extensive and acclaimed career in theatre, including roles in plays like "Hamlet", "Death of a Salesman", and "Waiting for Godot".
If you were actually asking about someone named John Hagy, please provide more context or information about him so I can assist you further.