Cajun is French, but "Iko Iko" isn't Cajun. According to "Sugar Boy" Crawford himself, he took the lyrics from Mardi Gras Indian chants. The only part I can identify, "Jock-a-mo feena" is straight Mobilian Jargon, i.e. čokmo fehna "very good". If there's any Cajun French in the song, neither I or anyone else has been able to tease out what it is--at least, as far as I know, which is why I asked the question.