Gredown, Atlas & Seaboard: The Unpublished Bog Beast
The story, titled 'The Sun-Spawn Stalks', is thought to have originally been slated for issue #4 of Tales Of Evil but as the title had finished after issue #3 it was shelved, until it was sold with other inventory stock and eventually turned up in the Australian Gredown book, Fearful Spectres.
Bog Beast appeared in three stories in the original Atlas/Seaboard titles, Tales Of Evil #2, Tales Of Evil #3 and Weird Tales of the Macabre #2. All three stories can be found in Australian Gredowns, The Brute has the story The Fifty Dollar Body (John Albano & Jack Sparling - Tales Of Evil #2) and the title you're looking at above has the following stories:
The Bog Beast (Gabe Levy & Badia Romero - Weird Tales Of The Macabre #2)
Vampire Killer Still At Large (Gabe Levy & Badia Romero - Tales of Evil #3)
The Sun-Spawn Stalks (Gabe Levy(?) & Badia Romero) - unpublished by Atlas.
What we now have is a genuine gem of a story, unpublished and I'm sure that a lot of people will be seeing this for the first ever time. Enjoy!