Zushakon (or Zuchequon or Zul-Che-Quon) debuted in Kuttner's short story "Bells of Horror" (1939). The being is the son of Ubbo-Sathla, procreated by binary fission. Other sources, however, consider him the progeny of Shub-Niggurath and Hastur.
Zushakon is the god of death to the Mutsun tribe of California. Zushakon has an intense hatred of light and will slay anyone who exposes one of his sacred artifacts to it. He can be summoned by the ringing of three specially consecrated bells.
His arrival is heralded by the rapid darkening and chilling of the surrounding environment and the sound of flapping, as if produced by very large wings, steadily increasing in volume. Furthermore, all creatures nearby suffer an irritation of the eyes that is so severe, they are compelled to literally gouge them out. Upon his arrival, the surrounding shadows darken, thicken, swirl, and finally clot into his dreadful shape. It is not known whether the clot of darkness that forms is merely a gateway or the actual entity himself.
According to the famed occult detective Doctor Anton Zarnak, who witnessed Zushakon's arrival during an unsuccessful attempt to exorcise him from a client, Zushakon is an earth elemental and can be repelled by bright lights or by summoning the fire god Cthugha. The unfortunate victim, who died during the struggle, had dug up a mound that contained the remains of a Mutsun shaman. Inside, he found an obsidian tablet and a carving of a hooded, possibly winged, humanoid figure surrounded by toad-like beings prostrate in worship before it. Inscribed on the tablet was an ancient, now-extinct script promising death to anyone who exposed the contents of the barrow. It is very likely that the winged figure in the carving is Zushakon himself.
After he departs, Zushakon may return yet again during the first earthquake or solar eclipse following an earlier, successful summoning of him.
Read more about this topic: Henry Kuttner Deities