Gailler was a puppeteer and ventriloquist. The first three puppets for his theater were given to him by an innkeeper. From then on, he developed his business and performed mainly in southeastern Bavaria with a repertoire consisting of classical plays, but also of topical subjects, including the play Adele Spitzeder from his posthumous collection. In 1906, Gailler gave up his life as a travelling puppeteer and sold his theater to Ludwig Walch. He died a year later in Berchtesgaden.