Some nine years ago, I published this post on Andrew Ferguson’s NYRSF piece on unpublished R. A. Lafferty works. These included:
Loup Garou, a werewolf mystery
Civil Blood, an anti-communist novel
Antonio Vescovo, a very early novel described as “a cross between Rabelais and The Lives of the Saints”
Dark Shine, about gifted children and an evil protagonist, and
When All the World Was Young, a plague novel in which everyone over the age of 10 is killed.
I also knew about the unpublished “In a Green Tree” novels:
Grasshoppers and Wild Honey 1928-1942 (first two chapters published, the rest unpublished)
Deep Scars of the Thunder 1942-1960
Incidents of Travel in Flatland 1960-1978
(A project fifth volume, In the Akrokeraunian Mountains 1978-1990, was evidently started but never completed.)
I was also aware of the third and fourth volumes in the Coscuin Chronicles series:
Sardinian Summer
First and Last Island
However, this wiki (evidently created by Ferguson) includes still more novels I haven’t heard about before:
Esteban, “a historical novel tracking the life and travels of the African slave who was the first ‘white’ (i.e., non-Native) man to enter much of what would become the southwestern United States”
Fair Hills of Ocean, Oh!, “About a dolphin who is a quadruple-agent spy and the invasion of dry land by the king of the oceans.”
Iron Tongue of Midnight (I know nothing about, except it shares the same title as a 1988 Lafferty poem)
Mantis (evidently a mystery novel)
Not listed there, and only listed on a couple of dubious webpages, so I have my doubts as to whether it actually exists, is The Giant Ratchet of Sumatra (with Sharon Scott). There is a reference to a first chapter manuscript in the University of Tulsa archives, but I see no sign that it had ever been completed.
Excluding the dubious and unfinished, by my count that’s fourteen unpublished Lafferty novels…