Luster is an African-American, the son of Frony Gibson, and a servant to the Compson family. He is Benjy's caretaker and playmate in 1928, when Benjy is thirty-three years old. The Compson Appendix says that Luster is 14 years old at this time and “was not only capable of the complete care and security of an idiot twice his age and three times his size, but could keep him entertained (348).
Glicksberg, Charles I. “William Faulkner and the Negro Problem.” Phylon (1940-1956) 10.2 (1949): 153-160.
Minnick, Lisa. “Representations of Speech and Attitudes about Race in The Sound and the Fury.” Dialect and Dichotomy: Literary Representations of African American Speech. Tuscaloosa: The University of Alabama Press, 2004.