As you say, there is no Wikipedia article on the novel, or rather what coverage there is has been integrated into an article primarily on the cartoon; possibly this is because it is hard to find reliable sources for referencing and proving the notability of the work. The most natural evolution would be to separate the differences out into a section, which could later be split into a standalone article.
The book is available in hardcover, paperback, "mass-market" paperback and audio cassettes (with a snazzy cover).
As you say, there is no Wikipedia article on the novel, or rather what coverage there is has been integrated into an article primarily on the cartoon; possibly this is because it is hard to find reliable sources for referencing and proving the notability of the work. The most natural evolution would be to separate the differences out into a section, which could later be split into a standalone article.