Growing her worms is a tricky process for Astrid that needs close supervision. But when Wurmhol was still in his vat, Astrid was arrested by Dayton for having trashed the sidewalk where her worms relieved themselves. And by the time she was released, Wurmhol had grown too big to be kept on a leash! So, she now let's him take himself off for walks in the sewers, where he gobbles up everything he encounters.