Johannes Eppler, also known as Hans Eppler, John Eppler, and Hussein Gaafer, (born 1914)[1] was a World War II Abwehr spy, a German who had been raised in Egypt by his Egyptian stepfather. Eppler was arrested in July 1942 and is the subject of MI5 file KV 2/1467. He is the subject of a book by Leonard Mosley, "The Cat and the Mice", and is again referenced in Mosley's The Druid.