He ate himself to death...

I agree; that was a bizarre ending. I wonder if Diamond Jim had any love children...possibly only because I love this quote:

"I heard your dad went into a restaurant and ate everything in the restaurant and they had to close the restaurant." Ralph Wiggum, The Simpsons

Still, this movie is an interesting, if little-known nowadays, portrait of this larger-than-life individual. I give it a thumbs-up.