The first book of the Illuminatus! trilogy, detailing the journeys of Hagbard Celine in the yellow submarine Lief Erikson which mysteriously changes it's name to Leif Erikson in the two following volumes, The Golden Apple and Leviathan.
Written by Robert Anton Wilson and Robert Shea in 1975, this was one of the earliest books to prominently feature discordianism, and it is also wickedly funny.
Information about the whole work is at the Illuminatus! trilogy, information about the meaning of the title is at eye in the pyramid.