Like 'Dracula', this is pretty slow by todays standards, but it's still an important and chilling landmark.
Boris Karloff plays Im-ho-tep, who is revived in modern day 3,700 years after being buried alive for stealing a sacred scroll. He believes Zita Johann is the reincarnation of his former love, and tries to steal her away from hero David Manners.
There are a few disappointing elements, the mummy isn't seen wrapped for very long, indeed, this is the most 'human' member of the living dead on film; and on the whole, it's more of a love story than a horror movie. However, these let-downs are out weighed by the good points: Karloff is great as usual, and the opening scene, in which Bramwell Fletcher is driven mad by the Mummy going "for a little walk", is the stuff of legends.
Along with 'Dracula' amd 'Frankenstein', this film set the foundations for the Universal series that turned making horror movies into creating art. 'The Mummy's Hand' was a loose, but excellent, sequel.