Quo Vadis (1951)

Continuity mistake: When the giant is fighting the bull, in the long shots the bulls horns are white, but in the closeups, they're black.

Emperor Nero: Is it possible that human beings can produce such a sound?
Petronius: Yes, when they've been pushed too far.

Trivia: Galva, the general who claims the emperor's throne after Nero's death, didn't last long as an emperor himself: just four months later, he was murdered by his Pretorian Guardsmen.