I just re-watched Apocalypse Now this past week, and once again enjoyed Hopper's performance as the crazed photojournalist, a "disciple" of the mysterious Col. Kurtz (Marlon Brando); the part wasn't included in the original screenplay, and was largely improvised by Hopper. The photog is actually inspired by the harlequin from Joseph Conrad's Heart of Darkness, upon which Apocalypse is based.
This is the way the world ends! Not with a bang, with a whimper. And with a whimper, I'm splitting, jack!