David played Count Saknussem in the film "Journey to the Center of the Earth" (1959). From 1966 to 1971, David portrayed various characters on ABC's daytime phenomenon "Dark Shadows". His many roles on "Dark Shadows" included Matthew Morgan, Ben Stokes, Professor T. Elliot Stokes, Sandor Rakosi, Count Petofi, Timothy Stokes (Parallel Time), Mordecai Grimes, and Ben Stokes (Parallel Time). David also played roles (different roles in each) in each of the spinoff movies - "House of Dark Shadows" (1970, playing Professor T. Elliot Stokes); and "Night of Dark Shadows" (1971, playing Reverend Strack).