The Wolf Man is a 1941 American horror film directed by George Waggner and written by Curt Siodmak. The title role is played by Lon Chaney Jr. and the title character has had a significant impact on Hollywood's representations of the werewolf tale. The film is Universal Pictures' second werewolf feature, following the less commercially successful Werewolf of London six years prior (1935). This picture is a part of the Universal Monsters franchise, and its production has received critical acclaim. Following the success of this film, Lon Chaney Jr. would return as "The Wolf Man" in four sequels, the first of which was Frankenstein Meets the Wolf Man in 1943.

In the original picture, Chaney did not experience an on-screen facial metamorphosis from man to wolf, as he did in all sequels. Only the last 10 minutes of the show featured the lap-dissolved progressive makeups, which were displayed discreetly. Larry takes off his shoes and socks in the first transition. His feet have turned hairy and have grown into massive paws (courtesy of uncomfortable "boots" made of hard rubber, covered in yak hair). In the closing scene, the werewolf uses the traditional approach to gradually return to Larry Talbot's human form.

The makeup and transition moments have become legendary, yet most of the stories are untrue. Chaney's change from man to monster took a long time to complete; the entire costume took five to six hours to apply and an hour to remove. In “Werewolf of London” (1935), Jack Pierce designed it for Henry Hull, but Hull claimed that the disguise made little sense within the plot because "Dr. Glendon" had to be identifiable by the characters even in his werewolf form. Pierce was tasked with creating a second version that revealed more of Hull's face. Pierce then reused his 1941 film's original concept.

As the images were shot frame by frame, Chaney stated he was forced to sit immobile for hours. He stated he was left seated while the crew took a break for lunch at times, and he was also ambiguous about using the restroom. Special effects men allegedly hammered small finishing nails into the skin on the sides of Chaney's hands to keep them still for close-ups, according to Chaney.

However, studio logs show that during the filming of Abbott and Costello Meet Frankenstein (1948), the entire crew, including Chaney, took a two-hour break during a transformation and finished the scene later that day (though the makeup for "Abbott and Costello Meet Frankenstein" had been redesigned by Bud Westmore over the original Jack Pierce makeup). A plaster mold was created to keep his head steady while his image was captured and his outline was drawn on glass panes in front of the camera. Chaney then went to makeup artist Jack Pierce's office, where Pierce used grease paint, a rubber snout appliance, and a series of wigs to glue Chaney's face together. Chaney next headed to makeup artist Jack Pierce's department, where Pierce bonded layers of yak hair to Chaney's face using grease paint, a rubber snout gadget, and a succession of wigs.

Chaney would return to the set, line himself up using the glass panes as a guide, and film many feet. Chaney would then go back to the makeup department. A fresh layer would be added to signify that the change has progressed. After that, he'd go back to the sound stage to film. This was repeated approximately a half-dozen times. On screen, Talbot's lap dissolve change took only seconds, whereas Chaney's took about ten hours.

In all of the 1940's cinematic appearances, "The Wolf Man'' is the only Universal monster played by the same actor. "[The wolf man] was my baby," Lon Chaney Jr. repeatedly stated in interviews. The film remains the most recognizable and most cherished interpretation of the [werewolf] tale,' according to the cinema reference book "1001 Movies You Must See Before You Die". "The Wolf Man" is also one of three top-tier Universal Studios monsters without a direct literary source,"The Mummy" and the "Creature from the Black Lagoon" are the other two.