Klaus found his way onto the stage and acting through staged readings from his novels. Since 2018, he has also been performing as a cabaret artist together with investigative journalist Michael Nikbakhsh, including regularly at Vienna's Rabenhof Theater and Kulisse Wien. In 2025, he can be seen in a duo with Caroline Athanasiadis in the musical satire “Kinderlieder aus der Hölle”. Together with Miriam Hie, he will host the well-known cabaret mixed show “Katze im Sack” in the 24/25 season.