Marc Brown appeared in an episode of Mister Rogers' Neighborhood, and Arthur (a puppet of him, anyway) visited the Land of Make-Believe, with Michael Yarmush, his voice actor at the time, reprising his role for the visit.note Mister Rogers had previously made a guest appearance in the Arthur episode, "Arthur Meets Mister Rogers", wherein he (depicted as a cartoon aardvark) befriends the title character. This episode was originally meant to promote that appearance, but it aired much later than intended due to Schedule Slip.
The Living Books adaptation of Stellaluna has an Easter Egg that allows the player to access a gallery of bat-inspired cartoons. One of these is of Arthur hanging upside down from a branch as Stellaluna tells him he's in the wrong book. This should come as no surprise, sinceLiving Booksalso released fiveArthurgames.note Arthur's Teacher Trouble, Arthur's Birthday, Arthur's Reading Race, Arthur's Computer Adventure, and D.W. the Picky Eater.
Disney's Doug: In the series' first episode, "Doug's Last Birthday", Judy tells Doug that he cancelled his eleventh birthday because he didn't want to move to Bluffington. She tells him that if he got his way, he would have stayed in Bloatsburg with his old friends, Arthur and Buster, and never met his new friends. To drive the point home, the expies of the characters resembled the real thing very eerily◊.