The clearly washed-up superhero Captain Blasto is played by—who else—Adam West.
Scott Menville worked at the grocery store, the movie theatre, diagnosed Angelica's broken leg, and failed to change a diaper in Didi's home economics class.
The Other Darrin: After David Doyle's death, Joe Alaskey took over as Grandpa Lou's voice actor.
Also, when Christine Cavanaugh — the original voice of Chuckie Finster — left the show due to maternity leave, she was replaced by Nancy Cartwright (from The Simpsons). Not that many fans liked Ms. Cartwright's take on Chuckie. It sounded too Ralph Wiggum.
Talking to Himself: Phil, Lil, and their mother were all voiced by Kath Soucie. Also, Michael Bell voiced both Drew and Chaz. Didi and her mother were both Melanie Chartoff.
In Mexico, it's Dil and Susie. In Sweden, Tommy and Angelica.
Un-Canceled: The show originally ended in 1994 with little fanfare, only for the network to notice that reruns consistently had the same ratings as the first run episodes. It was brought back in 1998, for better or worse.
What Could Have Been: Originally 20th Century Fox had a deal with Nickelodeon to release movies of the Nicktoons in 1993 but this fell through. Subverted with a theatrical movie coming out in 1998, released by Paramount.