The Metamorphosis was a book written by Franz Kafka. According to Harry Sullivan, it was about a giant cockroach. (PROSE: Nanomorphosis)
Flora Samsa implied that Kafka's story was based on his friend, and her great-great-great-great-great-great-great-uncle, Gregor Samsa, who had turned into an insect, although when she told the Seventh Doctor about it she did not mention the story's title or the author's name. (PROSE: Omegamorphosis)