The celebrated Munich cabaret artist Karl Valentin first came to prominence with his performance of his sketch Das Aquarium in 1908. This was also the moment at which he first established a comedy based upon extreme logic, wordplay and verbal misunderstanding, which in turn created a world in which his innocent 'matter-of-fact-ness' exposed the absurdities of social situations. This paper explores Valentin's use of his extraordinary skinniness to create both an effective comic persona and a comic physicality in his work. The authors argue that it was Valentin's slightly earlier sketch, Ich bin ein armer magerer Mann, when the comedian found his physical 'comic voice' and provide an analysis of the importance of physicality in Valentin's work, particularly in relation to this sketch. A new translation of the sketch is also provided.