A veteran of vaudeville, Broadway and television, Len Dressler is best known for his work in advertising. He portrayed the voice of the elfish Snap for Rice Krispies, Dig'em, the frog, for Kellogg's Sugar Smacks and a deep-voiced narrator for Marlboro cigarettes. His most enduring work came, in 1959, when he was picked to be the voice of the Jolly Green Giant for the Minnesota Valley Canning Company. Although he had only three words, "Ho Ho Ho", in the commercials, its popularity placed his voice among the most heard sounds of the 1960s and ‘70s. Dressler reprised the role in a series of new commercials, filmed in 2000, celebrating the company's seventy-fifth anniversary.
Although little known as a singer, in the United States, Dressler had a very successful career in Europe. A member of Jamie Silva's The J's, in 1963, he formed a jingle-singing quartet, Singers Unlimited, featuring Gene Puerling of the Hi-Los, Don Shelton and Bonnie Herman, in 1967. Signed by the German MPS Records label, the group recorded fifteen albums, between 1971 and 1981.