This wasn't written by Norman Bridwell, but by Gail Herman. It's an adaptation of the episode "The Monster in 3-8" from the 2003 PBS animated series, Clifford's Puppy Days. The script was written by ... someone who would later go on to pen The Hunger Games series.
The illustrations were apparently stills from the series, done by Barry Goldberg. There is a slight visual difference from Bridwell's original Clifford books, done to make it easier on the animators. There is also a brighter color palette, with an unhealthy emphasis on pastels.
I had three Clifford books when I was a small kid in the 1970s. My absolute favorite was Clifford the Small Red Puppy, so here we are. Happy Halloween 2025, everyone, when I am nearly 56 years old ... emphasis on old, unfortunately. It was funny to see a lop-eared rabbit dwarfing Clifford ... although the French Lop rabbit breed can hit 20 pounds. Better watch out, Clifford.
This book about Clifford's first Halloween did have a couple of genuinely funny moments, but the overall premise was predictable.
You can currently find most of the Clifford books at the Internet Archive.