For years, Pluto has been accepted as Yuggoth's real world equivalent, however the newly discovered "Planet Nine" fits the described characteristics of H.P. Lovecraft's dark world much more.

"Yuggoth... is a strange dark orb at the very rim of our solar system... There are mighty cities on Yuggoth—great tiers of terraced towers built of black stone... The sun shines there no brighter than a star, but the beings need no light. They have other subtler senses, and put no windows in their great houses and temples... The black rivers of pitch that flow under those mysterious cyclopean bridges—things built by some elder race extinct and forgotten before the beings came to Yuggoth from the ultimate voids—ought to be enough to make any man a Dante or Poe if he can keep sane long enough to tell what he has seen..."

- H.P. Lovecraft, "The Whisperer in the Darkness"