Castor Oyl is a fictional character, created in 1920 by cartoonist Elzie Crisler Segar for his comic strip Thimble Theatre, now known as Popeye. Castor Oyl is Olive Oyl's older brother, debuting in Thimble Theatre on January 14, 1920. He was the protagonist of the strip for years before the first appearance of the Popeye character in January 1929. A quick-witted yet diminutive adventurer, Castor Oyl continued to be an important character in Segar's Popeye strip, but played virtually no role in the Popeye theatrical cartoons produced first by Fleischer Studios and then by Famous Studios. His most prominent appearance in the series is as a member of Popeye's orchestra in the 1935 short The Spinach Overture.