The lyrics by Giac pretty well sum up the words that I can find in a few minutes with Yahoo. There is a variation by the Grateful Dead on www3.clearlight.com/~acsa/songfile (many lyrics here). A version, essentially the same as given by Giac, played and sung by the Dead on www.4inprint.com/neil/jukebox/jukea.htm. A version by the Dixie Cups is mentioned also. The site www.cajunfrenchmusic.org and a letter by Dr. John pretty much indicate that "Jocamo" is jester and Iko is unknown.