Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a Taiwan-Hong Kong-American horror/animals run amok movie starring Clint Walker as zoologist Dr. Morgan Bates, and Eartha Kitt as a snake priestess. It uses a lot of footage from the Hong Kong movie "Calamity of Snakes" (which you can read about here) as well as a couple of other movies. (Almost all of the snake violence seen in Calamity is missing from this movie. They cut out all of the disturbing scenes of snakes actually being smashed, but, and burned to death.) I'm not going to try to do a full summary of this crazy mashup of a movie. I'll just put up some pictures from it, along with some footage it uses that I have already used on the Calamity of Snakes page. You can read a good summary of the movie, and watch the whole thing on The Silver Scream, and there's another good discussion of it on The Daily Grindhouse.
When the movie begins we see Jason, a young boy, in a jungle (where he is frightened by a snake in a tree) with his father and a guide. They are sarching for Jason's sister who joined a cult that worships snakes. Just as they find her, she is sacrificed by the cult. Their guide is killed and the boy kills the cult leader, who puts a curse on him and his family.
Forty years later, Jason owns a construction company. The crew finds a pit full of snakes on the site of a new apartment building they are building. They burn the snakes with flamethrowers and hire a snake master to kill a giant warrior python that is the leader of the snakes. (The idea of an army of snakes with a leader is even more absurd than an organized herd of cats.)
Jason's wife Michelle has been having bad dreams about the snake cult so she asks advice from a scholar. He tells her that in his opinion "...there exists on earth a secret society directly linked to the awesome power of the serpent world." She decides she needs to go visit the cult in the Mexican desert. She visits Dr. Morgan in California. He's an expert on snake cults, and, along with his assistants, and they all meet up in the desert at the snake cult cave hideout.
In the cave we see Eartha Kitt, the priestess of the snake cult, and some of cult members dancing and handling snakes. Some of them dance with snakes held in their mouths. But when they discover Michelle and the others, the movie turns into an action movie with a violent gun battle.
Back in Hong Kong we see the now-finished apartment building that has been overrun with thousands of snakes. Snakes overwhelm a man in his car in the garage. They swarm up the stairs and halls. They fill the lobby and attack people at a party and kill a woman in her bathtub. Most of this footage was taken from Calamity of Snakes, so I'm doing the same here. Someone eventually calls the fire department and they fight the snakes and the new warrior python, and, Spoiler alert, eventually burn it to death along with Jason.
Eartha Kitt has the last word with a warning about not bothering snakes, saying something like this: ...wherever they crawl on their bellies through this world they will not allow themselves to be stepped on with impunity.