Starckdeutsch (literally, strong German, albeit with ck for k, as dictated by the phonetics of the variant), also called Siegfriedsch and Kauderdeutsch, is an imagined language created by Matthias Koeppel, a German painter and poet and self-proclaimed Sprachkünstler (artist of language). It has some resemblance to Middle High German (Mittelhochdeutsch).
Matthias Koeppel started to write humorous poems in "Starckdeutsch" in 1972. A collection of them was published as Starckdeutsch. Sämtliche Gedichte in 1981.