Part of a phrase in HP Lovecraft's
Cthulhu mythos. Translates roughly to, "dreams," "sleeps," or "waits."
The phrase - Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn - translates to, "In his house at R'lyeh, dead Cthulhu waits
dreaming."
It is often shortened to, "
Cthulhu fhtagn," which loosely translates to, "Cthulhu waits," or "Cthulhu dreams."