"Later Alligator", based on a 12-bar blues chord structure was written by Louisiana songwriter Robert Charles Guidry and first recorded by him under his professional name "Bobby Charles" in 1955. Guidry, a Cajun musician, adopted a New Orleans-influenced blues style for the recording. He also wrote "Walking to New Orleans", which was recorded by Fats Domino.
The most famous recording of the song, however, was that created on December 12, 1955 by Bill Haley & His Comets at a recording session for Decca Records. Unlike most of Haley's recordings for Decca, which were created at the Pythian Temple studio in New York City, "Alligator" and its flip-side, "The Paper Boy (On Main Street U.S.A.)", was recorded at the Decca Building in New York. The song was featured in Rock Around the Clock, a musical film Haley and the Comets began shooting in January 1956. Decca records released this disk on February 1, 1956 in both 45 and 78 formats.
Haley's arrangement of the song is faster-paced than Guidry's original, and in particular the addition of a two-four beat changed the song from a rhythm and blues "shuffle" to rock and roll. The song also has a more light-hearted beat than the original, starting out with a high-pitched, childlike voice (belonging to Haley's lead guitarist, Franny Beecher) reciting the title of the song. The ending of the song was virtually identical to the conclusion of Haley's earlier hit, "Shake, Rattle and Roll".
Bill Haley's recording of "See You Later, Alligator" popularized a catchphrase already in use at the time, and Princess Margaret of the United Kingdom was quoted as saying it (this is related in a biography of the Princess published in the early 1960s). It would become Haley's third and final million-selling single, although it did not hit the top of the American charts