Answer: Swing Music Fans

Colloquialisms and common phrases often have origins lost to time or translation. Most Americans have heard the phrase “see you later, alligator” and simply chalked the peculiar turn of word up to strangeness for the sake of strangeness. The phrase actually has its origin in 1930s jive talk, the argot of jazz and swing communities centered around Harlem, wherein alligator became a reference to well dressed fans of jazz and swing music (possibly as an allusion to the popularity among alligator skin clothing accents like shoes and belts among said fans).

“See you later, alligator” then isn’t as much a silly random turn of phrase as it was a way for fans of the music and the musicians themselves to reference each other with an insider’s nod.