Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is that psychedelic movie where a Harvard brainiac eats some Mexican magic mushrooms and gets inside an isolation tank and then freaks out so bad he turns into an ape man and eats a raw sheep. But before that, he goes into a Mexican cave with some Hinchi Indians (whose hobby seems to be balancing the biggest rocks ever) and he takes the drug for the first time. It makes him hallucinate a lot of crazy things, including a big Burmese Python wrapped around his neck and a large spiny lizard that comes out of a knife wound in his hand. He also hallucinates a large monitor lizard, even though monitor lizards are not found anywhere in the Americas, only on other continents. Then the lizard turns into his wife who lies on the ground in a yoga pose. When he comes down from his trip, we see a real dead and disembowelled monitor lizard that he is told he killed. He refuses to believe it, but we see the mess he made and hope that it does not foreshadow anything he will do to his wife later in the movie.
We see a live monitor lizard and what looks like a stuffed dead one and then a recently killed one. They all look like Nile Monitors.The large spiny lizard is also a real live lizard like maybe a Desert Spiny Lizard.