Board Thread:News and Announcements/@comment-82.46.142.194-20130501185254/@comment-4848837-20130501191134

Feedback was not invented until Omniverse, and Upchuck was thought to be one species even by the writers at the time. Squidstrictor and Rocks do not exist. As for the rest of those aliens, they did not exist at the beginning of the series. The Ultimate Alien intro stayed the same from the beginning of the show, so none of these guys got incorporated later on.