"Mannish Boy" is a blues standard written by Muddy Waters, Mel London, and Bo Diddley (with Waters and Diddley being credited under their birth names).
First recorded in 1955 by Waters, it serves as an "answer song" to Bo Diddley's "I'm a Man",[1] which was in turn inspired by Waters' and Willie Dixon's "Hoochie Coochie Man".
"Mannish Boy" features a repeating stop-time figure on one chord throughout the song.
Although the song contains sexual boasting, its repetition of "I'm a man, I spell M, A child, N" was understood as political. Waters had recently left the South for Chicago.
"Growing up in the South, African-Americans [would] never be referred to as a man – but as 'boy'. In this context, the song is an assertion of black manhood."