Which author wrote the novella The Metamorphosis?

Kafka, and the opening sentence is one of the most argued-over translations in literature. Gregor Samsa wakes transformed into an ungeheueres Ungeziefer - literally a monstrous vermin, with Ungeziefer historically meaning an animal unfit for sacrifice. Not cockroach, not beetle, not insect. Kafka wrote to his publisher explicitly forbidding any illustration of the creature on the cover.

That refusal matters because the story works by not letting you see it. The family's reaction is the subject, and the horror is bureaucratic and domestic - Gregor's first thought is that he will miss his train and lose his job, and his employer sends someone round within the hour to ask why he is late.

Kafka asked his friend Max Brod to burn everything unpublished when he died, and Brod refused - which is why The Trial, The Castle and Amerika exist. Kafka published very little in his lifetime and worked at an insurance institute assessing workplace injury claims, which is not a coincidence: his day job was the paperwork of people being maimed by machinery, adjudicated by an unreachable institution.