Bastei Verlag, enamoured by the success of "Bessy", asked Vandersteen to provide a second weekly series. With the popularity of superheroes, especially "Batman", in Belgium and Germpany in these years, Vandersteen proposed a spinoff series of "Suske en Wiske", based on "Jerom", the strongman of the series. Called "Wastl" in German, 173 stories were produced between 1968 and 1972, with a publication that reached 150,000 copies at its summit. The best of these stories were published in Dutch as well, just like it was done with the later "Bessy"'s, but the weakness of the stories ended the series after only four years.