In his autobiography, Harpo explained that Milton became Gummo because he crept about the theater like a gumshoe detective. Other sources reported that Gummo was the family's hypochondriac, having been the sickliest of the brothers in childhood, and therefore wore rubber overshoes, called gumshoes, in all kinds of weather. Still others reported that Milton was the troupe's best dancer, and dance shoes tended to have rubber soles. Groucho stated that the source of the name was Gummo wearing galoshes. Whatever the details, the name relates to rubber-soled shoes.