From Wikipedia:
Chthon is a science fiction novel by American writer Piers Anthony, originally released in 1967. It was Anthony’s first published novel, and was nominated for both the Nebula Award for Best Novel in 1967 and the Hugo Award for Best Novel in 1968.
Shown here is a British paperback edition published by Panther Books in 1972. All-caps Gothic Round is paired up with Helvetica on the cover. The cover art is uncredited.
[More info on ISFDB]