Hastur was stated to be the half-brother of Cthulhu -and there was no love lost between the two. Laban Shrewsbury used the Elder Sign to command Hastur's Byakhee to be transport in his war against Cthulhu.
Five stories collected as the novel "THE TRIAL OF CTHULHU". The Arkham House hardbound was,like just about all their work, out of print, but Ballantine was able to publish it as a paperback, now long out of print...
Hastur was stated to be the half-brother of Cthulhu -and there was no love lost between the two. Lab