The Crouching Beast is a 1928 spy thriller novel by the British author Valentine Williams. It is part of his series of novels and short stories featuring the character of "Clubfoot", the alias of Doctor Adolph Grunt a brilliant but sinister German secret service mastermind. It is set in Constantinople, capital of the Ottoman Empire, during the First World War.
In 1935 it was adapted into a British film of the same title directed by Victor Hanbury and starring Fritz Kortner, Wynne Gibson and Andrews Engelmann.