The show was cancelled following the death of John Ritter, who voiced Clifford in this series. The voice was irreplaceable.
The show is based on the books written by Norman Bridwell.
A prequel called "Clifford's Puppy Days" was created in 2003 the same year John Ritter died.
Cleo (Cree Summer) says the first line in the series, and Clifford (John Ritter) says the last.
John Ritter (Clifford), Kel Mitchell (T-Bone), and Cree Summer (Cleo) each starred on a successful sitcom prior to this show. Ritter starred on "Three's Company" and 8 Simple Rules For Dating My Teenage Daughter" , Mitchell starred on "All That" and "Kenan & Kel", and Summer starred on "A Different World" and "Rugrats."