Clarence Aaron "Tod" Robbins (1888–1949), billed as C.A Robbins and better known as Tod Robbins, was an American author of horror and mystery fiction, particularly novels and short story collections.
Robbins attended Washington and Lee University (Lexington, Virginia) and—along with Mark W. Sheafe (1884?–1949) and Thornton Whitney Allen (1890–1944)—wrote the college song "Washington and Lee Swing." Sheafe wrote the tune in 1905, Allen set the music down on paper in 1909 and Robbins provided the words. The completed version was published in 1910.
Robbins authored two short story collections and several novels. His work often contains bizarre and frightening plots, sometimes influenced by writers like Oscar Wilde (Robbins' "The Living Portrait" is a homage to The Picture of Dorian Gray) and Robert W. Chambers. Robbins's Mysterious Martin (1912) is an early novel about a serial killer. His novel The Unholy Three (1917) was twice adapted for the screen, a silent version directed by Tod Browning in 1925 and a sound version directed by Jack Conway in 1930; both adaptations starred Lon Chaney. Robbins was also the author of the short story "Spurs", which Browning used as the basis for Freaks (1932), a film which later developed a cult following. Some of Robbins's work was later reprinted in the "Creeps" series of horror anthologies edited by Charles Birkin.
E. F. Bleiler described Robbins' Who Wants A Green Bottle? as "excellent commercial fiction, with good little touches".