On Wakko’s Ringo accent:
Many wacky Wakko’s later, they still didn’t have the right voice. So during their last appointment of the morning, with voice actor Jess Harnell, Ruegger opened the almanac to a list of celebrities and asked Harnell to do his best impression of Elvis, Rodney Dangerfield, Jackie Gleason, Frank Sinatra, and other notable names. When the Beatles came up, Harnell proceeded to do every one of the Fab Four so well you could actually tell which individual band member he was mimicking at the moment. However, it was Harnell’s Ringo that struck a chord with the producers, so after a few tweaks, that became the voice of Wakko.
While you’re over there, be sure to take a listen to Yakko’s World and Rob Paulsen’s live version of Yakko’s World.