Cthulhu is a creation.
In John Glasby's "A Shadow from the Aeons", Cthulhu is seen by the narrator roaming the riverbank near Dominic Waldron's castle, and roaring
 The imprisoned Cthulhu is apparently the source of constant subconscious anxiety for all mankind, and is also the object of worship, both by many human cults (including some within New Zealand, Greenland, Louisiana, and the Chinese mountains) and by other Lovecraftian monsters (called Deep Ones and Mi-Go)

