Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
Charlie Chan was a very popular detective character in movies of the 20s and 30s. He's based on a series of popular mystery novels. This is one of 16 popular and lucrative movies made with Warner Oland, a Swedish man, starring as Chan. Everybody seemed to love Charlie Chan at the time, but today he's seen either as a heroic character and one of the first positive depictions of Asians in movies which previously stereotyped them as evil, or he is seen as a racist stereotype of a subservient mysterious Asian played by a Caucasian in Yellowface. I think both views are correct.
Here, Charlie Chan, his wife, and their 12 kids go to a circus, where one of the circus owners is strangled to death by a gorilla that somebody released just to kill him. This presents a mystery for Charlie Chan to solve. The first snake in the movie is a Burmese Python that shows up around the neck of Gangor the Hindu Snake Charmer. The second snake shows up on a train when somebody drops it through the window of Chan's sleeper car to kill him. He wakes up to see the snake on his bed and reaches over to turn on his son's record player, which was conveniently left next to the bed with Middle-Eastern snake-charmer horn music already cued up from when his son played it earlier. When the snake hears the music, it immediately rears up and opens its hood like a snake charmer's cobra. (The myth is that cobras rise up and dance to horn music.) Chan's Number One Son comes into the bedroom and sees the snake, then he takes out a gun and shoots it dead. Charlie says that the person who used the snake to kill him will make another attempt after but not right away, but he says it, as he always talks, in mangled English that makes him sound mysteriously wise. The snake on the bed is a fake cobra, but the snake that was put through the window was alive. It is too dark to identify, but I suspect it is an Indigo Snake and not a live cobra.
Charlie Chan's aphorisms are why people loved him so much. I wrote down a few others from this movie just because I can:
"Curiosity responsible for cat needing 9 lives."
"Facts like photographic film - must be exposed before developing."
"Too soon to count chickens until eggs are in nest."
"Cannot tell where path lead until reach end of road."
"Silent witness sometimes speak loudest."
"Mind like parachute - only function when open."
"More than one way to remove skin from cat."