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 western farce with a lot of corny and not-so-funny comedy gags. Dean Martin, a cowboy, Alain Delon, a Spanish Nobleman, and Joey Bishop, an American Indian, are travelling from Shreveport Louisiana across the river into Texas through Comanche territory on their way to Mocassin Flats. Never mind that there is no river between Louisiana and Texas and that the country they travel through is classic California foothills and that, like all westerns, they eventually find themselves in the rocky Alabama Hills in the Owens Valley. Among the rocks they see a Comanche medicine man performing a Death Ceremony, shaking rattles dancing and chanting while a young Comanche woman sits tied up on a horse. The medicine man opens a large basket and we see two rattlesnakes crawl out of it. The woman screams and despite Martin's warnings not to, Delon rides down to save her. Martin says "He either likes girls or he's crazy about snakes." The medicine man rides away and Delon falls off his horse and gets snakebit on the leg. (Because all movie snakes always want to kill all humans.) Martin rides up in a hurry and starts shooting the snakes. (Because all snakes must die.) We see four of them laying around outside the basket. Close-ups show them to be crispy old dead snakes that have been propped up. (This movie was made before snarky guys at home had the capability to pause the picture, so you could get away with less realism.) Then follows the usual cowboy cut-and-suck snakebite treatment - Joey Bishop says "Make bleed," Dean Martin cuts the leg with his knife, and the Indian woman sucks out the poison. This works only in the movies, so don't try it at home. Delon faints and is sick for a couple of days but he recovers quickly because of some herbs she put on the bite wound. Only in the movies….
The live rattlesnakes we see appear to be Western Diamond-backed Rattlesnakes. The old dead ones are so faded that they have had a new pattern painted on them, so there's no telling what they were. It looks like small explosive charges were put in their mouths to simulate gunshots, because their heads are all blown off.