Old Georgie is the Valleymen's version of the devil. He is mentioned in Sloosha's Crossin' an' Ev'rythin' After - which consists solely of chapter 6.
If Sonmi is god to the Valleymen, Old Georgie is the devil. He is said to exist atop Mauna Kea, which is, in turn, a feared spot for the Valleymen.
In the film adaptation, Old Georgie is portrayed by actor Hugo Weaving. He appears as a vision to Tom Hanks' character. He is dressed in old, ruined black clothes and top hat, reminiscent of the dress worn by Adam Ewing in the opening scene of the 1849-set segment in the film. Zachry believed that Old Georgie was the one who "tripped the Fall" before being corrected by Meronym.