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 grade-Z gory horror/comedy about a group of sex and drug-obsessed young people (is there any other kind?) riding on a party bus they were told is going to a festival in the Nevada desert (similar to Burning Man). The bus driver leaves the main road and drives onto an isolated dirt road, then stops and gets out of the bus with the keys. The bus is then surrounded by a psychotic cult of devil worshiping cannibals who kill and eat half of the passengers then trap the others in the bus, calling for them to release one of the women who they claim is a virgin whose sacrifice will bring back the devil and usher in a new age of hell on earth.
The gang of devil worshipers includes two women in typical Burning Man outfits who are carrying a large albino python. They dance around erotically with the snake then put its head into the mouth of woman passenger they haven't killed yet. After the snake crawls into her stomach, one of the cultists cuts the woman open with a knife and pulls out the bloody snake.
The bus passengers discover that their driver was a phony who killed the real driver. When she comes back into the bus they capture her and find out that she's part of the cult. When her clothes are stripped off we see that she is covered with creepy tattoos, including snakes, lizards, and spiders. When she explodes and falls to the floor, the bus is suddenly filled with snakes, lizards, and spiders (that must have come from the tattoos). The creepy crawlies kill off some of the remaining passengers. Then as fast as they appeared, they all disappear. But unfortunately, the cult psychos did not disappear, and neither did the movie, which kept on going, and goring.
We see the snakes in the bus in flashes, so it's hard to see some of them very well. I did recognize a Burmese Python, a large albino Python, maybe a Ball Python, and a third snake that I don't know. It might be one of the Asian rat snakes or racers.