The Metamorphosis
by Franz Kafka (1883-1924). Translated into the public domain by Ian Johnston (b. 1938).

The Metamorphosis (in German, Die Verwandlung, "The Transformation") is a novella by Franz Kafka, first published in 1915, and arguably the most famous of his works along with the longer works The Trial and The Castle. The story begins with a traveling salesman, Gregor Samsa, waking to find himself transformed into a giant "monstrous vermin".

(Summary from Wikipedia)