In year 1920 and 1926 respectively he created his most famous puppets: comical father Spejbl and his rascal son Hurvínek.
In 1961, Velebný and flautist Jan Konopásek co-founded SHQ, initially part of the Spejbl and Hurvínek Theatre (thus Spejbl and Huvínek Quintet), but later extending into independent performances.