Based on Doyle's The Adventure of the Six Napoleons this is one of the few Universal films to use a canonical story as a main plot line. It turns out to be a very good film and one wishes that they might have done it more often.

This film debuts Rondo Hatton as "The Oxton Creeper". Unfortunately, Rondo had been diagnosed with the chronic disease acromegaly, a pituitary dysfunction causing bone enlargement of the head and hands. But, with a little help from the master of lighting effects, director Roy William Niell, Hatton became the perfect monster, a quiet, giant terror. He became so popular during the film that he was featured again in several spin-offs.