@MLE_online I don't know anything about the cartoon, but I just listened to "Kad bi svi ljudi na svijetu" and immediately recognized the tune as a variation of Skip to My Lou, an American folk tune. I looked up the discography, and Dedić credited the song to Peter Yarrow (of Peter, Paul and Mary). Perhaps something thought to be an instrumental version of the Dedić tune used on an American cartoon was actually an instrumental version of Skip to My Lou?