Arthur is in it's 20th season now, I think? It's all just guest stars and recycled plots at this point. It's animated in Flash now, so it looks all outta whack.
https://www.youtube.com/watch?v=qtI2KnaxjuQ
this is the episode that shows the origin of the opening title scene! i first watched it with two girls that i babysat (11 and 9 yrs old) and lost my shit (Im' 21 now), but the kids couldn't have cared less lol. the episode blew my mind
https://www.youtube.com/watch?v=qtI2KnaxjuQ