I always enjoy a movie with a strong pirate interest. In Cecil B. Demille's first Jean Lafitte movie, starring Fredrick March as the infamous pirate, his crew sings a little ditty that goes "Callaloo, Oh callaloo! The crab saw the monkey, and he didn't know what to do, so he hollered callalloo." They don't sing it all the way through. I don't know if it was an authentic folksong, or some writer's invention, and I'd like to find out too.
(If it rhymes I remember it forever, whether I want to or not.)