Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
You have to get past the bad acting and even worse racism of this pre-code adventure movie to enjoy it, but there is some nice set design and its highlights are Boris Karloff's evil madman of the Orient, Fu Manchu, and his "ugly and insignificant daughter" Fah Lo See (the always beautiful Myrna Loy) who gets her kicks out of torturing men. The movie is a good example of a lot of what could be shown in a movie before the Hayes code censorship kicked in a few years later - torture, kidnapping, forced drugging, opium dens, sadomasochistic sex kicks, homoeroticism, human sacrifice, interracial love, and incitement to kill and rape. It's the sort of stuff you can see on daytime TV today, but it must have been shocking in 1932. The movie also shows White Imperialists plundering the treasures of another culture, but that never seemed to bother Hollywood. The racism is so blatant that it's almost unbelievable. Karloff and Loy are both in yellowface makeup, and they have large shirtless black men for slaves. The Brits claim they will never understand "these Eastern races" and worry that Fu Manchu wants to take their "beautiful white girl." He does, and when he's about to sacrifice her he asks the crowd, whose costumes seem to represent men from all over Asia, if they want a maiden like her for their wife and they all cheer their approval. Then he tells them to "Kill the white man and take his women!"
The plot is simple - a British scientist goes to the Gobi Desert to find the lost treasure of Atilla the Hun, including a mask and sword which, if they fall into the hands of diabolical madman Fu Machu, will allow him to empower all of Asia rise up and conquer the world. Fu Manchu kidnaps him before he goes to China and tortures him (under a large bell) but he refuses to talk. Meanwhile, his daughter Sheila, her boyfriend Terrence and others go and dig up the treasures, but then most of them get captured by Fu Manchu. One of the British agents sneaks around searching for Fu Manchu's lair and finds it when he falls through a trap door into an underground dirt chamber where gopher snakes are suspended from wires and other snakes crawl on the floor.
Meahwhile, Terrence is strapped to a table while Fu Manchu concocts a serum he describes as distilled from dragon's blood, the organs of different reptiles, and mixed with a magic brew of the sacred 7 herbs. Among the ingredients of the serum we see glass containers containing baby rattlesnakes, tarantulas, and a live Gila Monster that crawls out of the jar. Fu Manchu takes a tarantula out of a container holding other tarantulas, a Gila Monster, some some small snakes, and another lizard, maybe a Chuckwalla. He sticks a needle in it to add its venom to the serum. Then he picks up some tongs and pulls out a Burmese Python and makes it bite the arm one of his black slaves (who later dies) then he draws the slave's blood and adds it to the serum. The serum is used to make Terrence a slave to Fu Manchu's commands.
The rattlesnakes might be red diamond rattlesnakes or maybe western diamondbacks. I don't know what the smaller snakes are. The snakes in the underground chamber are live gopher snakes. One is tied to something to make it hang straight down, and the other is raised on a wire to make it look more menacing, then it is lowered. A live Burmese Python is used in the serum scene.