Yima was a childe of the Nosferatu Antediluvian from the time before Caine cursed him, being one of the 4th generation Nosferatu known as Nictuku, who were blood bonded since their Embrace by Absimiliard.
This vampire was Embraced before the Deluge. However, instead of following the hunts of his sire, Yima was a scholar and treated the kine with fairness. He foresaw the Deluge in a way similar to Noah, and retreated into subterranean caverns to endure the devastation.
There are two conflicting tales on Yima's fate. One is that the clan curse of the Nosferatu shattered his mind, leaving him diseased and mad within his domain, filled with animals and humans that serve him as feeding stock. The other is that Caine remembered his great-grandchilde fondly and spared him, making him the only Nosferatu without the curse. Many Nosferatu have spent their unlives trying to find Yima and gain something of his blood, for it is claimed that only the blood of Yima can cure a Nosferatu from their hideous appearance.
In a letter written on 10/31/00, Calebros expressed his belief that the Yima is just "another story of the Nictuku" pondering that a flawless ancestor would do nothing else but destroy his vile cousins.
There is a great debate as to whether or not Yima was struck with the curse. Some say he was because he inadvertently broke the law forbidding him to take disfigured things with him. Those who think he was not affected do so because they believe Caine favored him and thus took pity on him. Meaning that there is the possibility of a Nosferatu Methuselah untouched by the curse. In essence, Yima is to the Nosferatu what the Holy Grail is to Christian knights.