The eternal Guide of Dreamworld, "the Most Ancient One and The Prolonged of Life" as he is called in the Necronomicon. He guided Randolph Carter on his entrance into the world upon his disappearance from Arkham. NEW AS OF 2/20/94 The name is curiously similar to that of the old Arabian master alchemist Muhammad ibn Umail at-Tamimi (c. 900-960), who was know in Europe as "Senior" and whose "Book of the Silvery Water and Starry Earth" was translated into Latin as "De chemia." The book describes the end product of his mystical art as "that stone, which he that knoweth layeth upon his eyes, and he that knoweth it not, casteth upon a dunghill."
("Through the Gates of the Silver Key")