I have a “maybe”. V.C. Andrews wrote Flowers in the Attic and other books in a series about the characters in the book.
V.C. Andrews died and Andrew Neiderman wrote other books under the name of V.C. Andrews.
The wikipedia article for Garden of Shadows has:
“There is some dispute over whether this particular novel was written in part by Andrews before she died, or whether it was written entirely by Neiderman”.
Well, not exactly. The Campbell novel was entitled “All”, and Campbell certainly did finish it, although it wasn’t published until after his death (in the collection The Space Beyond"). I’ve read it. It’s a gruellingly unfriendly read, but I was curious to see how Heinlein changed things. Heinlein’s novel is incomparably better and easier to read (despite the racism – but it was written while we were fighting the Japanese, and you find that in damned near all pop fiction from the period)
Not exactly the same thing. My understanding is that Gaiman sent Pratchett what he had written, and got positive feedback, and they both worked on finishing the piece. The description in the Wikipedia article seems consistent with this.
An example of where one living writer turned something over to another to complete it, without apparently having much, if anything, to do with the completed novel is Lorelei of the Red Mist, which Leigh Brackett wrote the first half of, then handed over to Ray Bradbury (who would shortly be best man at her wedding to fellow writer Edmond Hamilton) to complete so that she could work on the screenplay for The Big Sleep. It’s unthinkable that Brackett wouldn’t have at least read through Bradbury’s finished version, but nobody says anything about the writing beyond this, so I’ve assumed that she didn’t require any major changes.
Yes, I definitely wouldn’t say it’s the same thing (Good Omens, that is). Most collaborations start with an idea by one of the writers, but they’re still collaborations, often with the original idea changed completely.
Not to mention The Watsons.
Surprised no mention of Dune 7 and 8. Frank Herbert died before completing the seventh Dune book but left a trove of notes behind outlining his plot. His son Brian worked with collaborator Kevin J. Anderson to finish the novel (split into two). I’m not going to lay any judgments on how closely the notes were followed, as the books rely heavily upon the son’s prequel books that were written prior to the discovery of the notes. Plus, the notes have never been published directly.