Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
"In the media circus of life, they were the main attraction."
Out of gas, a couple on a killing spree, Mikey and Mallory Knox, wander into a Navajo Hogan and offer to trade tobacco for gas. Inside there's an Indian man and his rattlesnake (either a Red Diamond Rattlesnake or a red Western Diamond-backed Rattlesnake.) They scream in fear of the snake then speak in broken English saying racist stuff like "how." The Indian guy is wearing rattlesnake heads attached to snakeskin bands his ankles. Later the Indian picks up the snake barehanded, puts it on his lap, and tells the story same as the lyrics to the pop song "The Snake" about a woman who found a frozen snake in the snow and took it home to heal it, but when it got better it bit her on the cheek. As she lay dying from the venom she asked it why it bit her. The snake justs says "You knew I was a snake!" Then the Indian puts the snake outside and tells it "Old man, go be a snake." After a bunch of psychedelic family trauma flashbacks and fancy camera effects, Mikey kills the indian. When he and Mallory leave, they see rattlesnakes on the ground everywhere and they both get bitten. We also see that Mikey took the rattlesnake head bands or boots from the Indian. They somehow get gas and drive all the way to a drug store which has several shelves with signs saying they're sold out of anti-venin (snake-bite juice.)
I think the Indian used magic to make the snakes attack Mikey and Mallory after they killed him, which makes them snakes used as weapons. That makes about as much sense as the possibility that hundreds of rattlesnakes are just lying around on the ground at night, so I'm sticking with it.