Oppo Rancisis, also known as The Dread Oppho, Aupoa the Undying, once characterized by the mad Sith sage Kaman al-Phoom as the "thing that cannot be described," was the nameless horror that slept, dead but dreaming, somewhere in the Jedi Temple on Coruscant, where a racial memory preserved his nightmarish visage as the epitome of all that is evil, disgusting, and immortal.
Rancisis served on the Jedi Council during the Separatist Crisis, offering advice in the form of deranged dreams projected into the minds of his hapless cultists. Many such cults arose around Rancisis during the Clone Wars, in the mountains of Manarai and the depths of the undercity, whose leaders were said to be deathless and soulless. Such cults sought to avoid the coming day of doom when Rancisis would dream the destruction of all life. In the meantime, Rancisis was apprenticed to Yaddle for a time and participated in the siege of Saleucami.
Rancisis was killed by Jedi traitor Sora Bulq, but death was hardly a setback for the Great Old Jedi Master... for as written in the Opponomicon: "That is not dead which can eternal lie / For he's a jolly good fellow, which nobody can deny."