Specifically the Titans of Ark - godlike beings who created Erfworld. At least three in number - although there may be more - and apparently serving as some kind of pantheon for the folk of Erfworld both for purposes of Iconography (since they seemed to be depicted in every throne room or command centre we've seen so far) and for purposes of blasphemy ("Titan's Testes!").
They are also responsible for the creation of the Artifacts that play such a crucial role in the realpolitik of the world they created.
Real World References
They possess a distinct resemblance to a late period Elvis Presley and impersonators thereof.