"I mentioned that making Good Omens 2 is half of what I've been working on, and will be working on for [the] next 18 months, and I said I'd tell you soon enough what the other secret project I've been working on is. It's this," Gaiman wrote in a blog post.
"And I cannot tell you how happy I am to be making it, and making it in the way that we're making it."
Gaiman and Douglas Mackinnon are co-showrunners on the project, and Hanelle M. Culpepper is lead director. Jermain Julien and Azhur Saleem will also direct episodes.
No casting has been announced yet.
This is how Gaiman described Anansi Boys in 2005: "My new novel is a scary, funny sort of story, which isn't exactly a thriller, and isn't really horror, and doesn't quite qualify as a ghost story (although it has at least one ghost in it), or a romantic comedy (although there are several romances in there, and it's certainly a comedy, except for the scary bits). If you have to classify it, it's probably a magical-horror-thriller-ghost-romantic-comedy-family-epic, although that leaves out the detective bits and much of the food."
In addition to Good Omens, Gaiman recently has collaborated on TV adaptations of his books, American Gods and The Sandman.