Boris Karloff is one of the most iconic names in horror. His face, be it as Frankenstein’s Monster, the Mummy, or even the Grinch, has been reprinted on countless t-shirts, coffee mugs, and tattoos. The new documentary, Boris Karloff: The Man Behind the Monster, is a deep dive into the actor’s long career and all its ups and downs. It’s a must-see for horror fans and film buffs in general.

Directed by Thomas Hamilton and written by Hamilton and Ron MacCloskey, the film, of course, gives warranted attention to some of Karloff’s most well-known movies, like Frankenstein, Bride of Frankenstein, The Black Cat, and How the Grinch Stole Christmas. But it also explores some of his lesser-known roles, including his early days in silent films and his stint on Broadway in the 1940s, when he performed in “Arsenic and Old Lace,” which revived his love of acting at a time when he was burned out on horror and felt typecast.

The doc features interviews with some of the genre’s heavy hitters, including Joe Dante, John Landis, Guillermo del Toro, Roger Corman, and Karloff’s daughter Sara, among many others, all of whom discuss his legacy and even his friendship with other horror icons like Vincent Price and Bela Lugosi. There are plenty of tidbits and interesting nuggets that will come as surprise to even the sharpest film buff and horror fan. For instance, Karloff had a dispute with director James Whale over the scene in Frankenstein in which the Monster throws Maria (Marilyn Harris) into a lake and accidentally drowns her. Karloff thought the scene was too much, and it was cut and censored from the film until the 1980s. It’s also neat to see someone like del Toro talk about seeing Frankenstein and Bride of Frankenstein for the first time and comparing it to a religious experience. All of this serves as a reminder that these performances are such an important part of film history.

The doc also links much of Karloff’s career to the story of Hollywood itself in the first half of the 20th Century, and that’s one of its greatest strengths. The creation of the Screen Actors Guild, which Lugosi and Karloff fought for, is addressed. That’s just one example. The negative effects of the Hays Code on the actor’s career, and horror in general, are also covered. This all gives the doc greater historical weight.

The movie does touch somewhat on his personal life, including his father’s abusive behavior, his mother’s struggles with mental health, and his issues being typecast because of his darker skin. He was Anglo-Indian. Yet, all of this is barely more than a mention. It’s a shame because there’s much there to explore regarding his personal story and how it impacted his career and the roles he chose or was forced to play to pay the bills.

Still, there’s so much to enjoy in Boris Karloff: The Man Behind the Monster. It’s likely that even the biggest horror fan will learn about an underrated Karloff film or two overshadowed by his roles in Frankenstein or The Mummy. This is the perfect type of documentary to stream this Halloween season, a fine tribute to one of horror’s biggest and most enduring stars. It’s also a reminder that his legacy still looms so large because of the pathos he put into his performances, even when playing a monster.

8.5 Out of 10