Verrett (b. New Orleans 1907, d. 1965) started his career with Johnny Brown’s band in 1924. He worked in taxi-dance places and later with his own band at the Fern cafe during the late twenties. He went on to perform, tour and record with Papa Celestin, Fats Domino, and the Noon Johnson bazooka trio. (See Al Rose and Edmond Souchon, New Orleans Jazz: A Family Album, p. 124)
Here is a picture of Harrison and another of him playing with the Papa Celestin band from the Tulane archive.
He didn’t just record with Fats Domino. Verrett was Fats’ brother-in-law and helped Domino get his own start in music. Early on, Fats did not want to play without Verrett.