Filmography
| Role | Title | Year | Character |
|---|---|---|---|
| Writer | Superman: La película | 1978 | |
| Writer | Superman II | 1980 | |
| Writer | Superman III | 1983 | |
| Writer | Bonnie y Clyde | 1967 | |
| Writer | Moonwalker | 1988 | |
| Writer | Superman II: El montaje de Richard Donner | 2006 | |
| Writer | Santa Claus: La película | 1985 | |
| Writer | Santa Claus: La película | 1985 | |
| Writer | ¿Qué me pasa, doctor? | 1972 | |
| Writer | Sheena, Reina de la Selva | 1984 | |
| Writer | Bajo sospecha | 1982 | |
| Writer | El asalto final (Hackers 2: Operación Takedown) | 2000 | |
| Actor | DeadTectives | 2018 | Lloyd |
| Writer | Michael Jackson History | 1997 | |
| Actor | Score: Compositores de Oscar | 2017 | Himself |
| Writer | It's a Bird, It's a Plane, It's Superman! | 1975 | |
| Writer | El día de los tramposos | 1970 | |
| Actor | T and T | Dick Decker | |
| Producer | 100 Bloody Acres | 2012 | |
| Producer | R.O.T.O.R. | 1987 | |
| Actor | Easy Riders, Raging Bulls | 2003 | Himself |
| Writer | Pistoleros en el infierno | 1972 | |
| Actor | Conversations on Alex North's Spartacus: The Celebration of a Masterpiece | 2010 | David Newman |