Acting for Two: Or three in the case of Grey DeLisle, who plays not just Emily Elizabeth but also her mother Caroline and her teacher Ms. Carrington.
Played straight with Cam Clarke, who played Emily Elizabeth's father Mark and Machiavelli.
Author Existence Failure: Not strictly related to Bridwell, but the reason the animated series was spun off to Clifford's Puppy Days and the main show was abandoned was because of John Ritter's untimely passing.
Casting Gag: Having T-Bone's friend Hamburger being specifically voiced by Kenan Thompson. Also their fast-food inspired names are a Shout-Out to All That.
The Danza: Frankie from "Little Big Pup" is voiced by Frankie Muniz.
Development Hell: Universal and Illumination Entertainment were planning to do a film based off Clifford for a 2016 release, but nothing came out after the announcement. By the time said year came around, it was clear Universal no longer wanted anything to do with the film anymore, as it was revealed their rights had expired and the project moved to Paramount.
No Export for You: The iPhone and iPad game are this to South America and Asia, as are the releases on the Leapfrog consoles. Most of the toys, however, are North America only, especially those that are not made by Scholastic themselves.
The Other Darrin: They did not replace any of the characters on the the show in the strictest sense, but in the original 80s specials, Emily Elizabeth was voiced by Alyson Court. On the 2000s series, she was voiced by Grey De Lisle. Possibly also Lampshaded by the fact that both had a vastly different art style from each other.
Outlived Its Creator: Norman Bridwell passed away on December 12th, 2014. At this point the TV show has stopped and has had no new episodes since 2005, but he has two books that is still unpublished. Also, the movie won't be released until 2016.