Hoot Koomi
Mentioned in Pyramids, Hoot Koomi is the high priest of the god Khefin, the Two-Faced God of Gateways (a la Janus on Roundworld). As the second most powerful priest in Djelibeybi, most priests see him as the "heir apparent" to Dios, not realizing that Dios is essentially immortal.
We don't know if he is any relation to Koomi of Smale, who also studied gods, albeit in a different way.
Annotation
Not a million miles away from Koot Hoomi[1], a Higher Intelligence who acted as a spirit guide to Theosophy's founder, Madame Blavatski. As only Blavatsky could see him, and as alas there will always be cynics, scoffers, and unbelievers, much mirth was made out of this assertion.