Jackie-boy was another lost TMNT concept. He accompanied a pitch that was accepted just prior to the sale of the brand to Viacom. The idea was that if there were Triceratons, surely there were other Saurian races out there as well. This guy was a pilot amongst a band of space pirates/fugitives.
Now, he's going to appear in my own book "Dirty Deeds" which I'm writing with TMNT and potential Ghostbusters collaborator Andres Ponce ([link]