Olson's poem puts two things side by side that don't belong together: a bright, ringed coral snake and the dead body of a pig. The speaker addresses the snake directly, calling it beautiful, even while picturing it in a pigsty, dry and rattling, and then inside the pig's belly. The image of a whole arm reaching into the animal is hard to look at, and the poem doesn't soften it.
Then something shifts. The snake "does walk out," and the poem says it turns winter to spring, as if its movement brings life back to a dead scene. The pig's eye stays "fixed upon nothing," which makes the final lines odd and unsettling: the speaker marvels at the snake's power, so great that the pig should love him.
The mood is strange, fascinated, and a little uneasy. Admiration and disgust sit together, and the broken punctuation and slashes make the poem feel as fractured as the scene it describes.