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 slow and tense independent movie that uses a snake used as a lethal weapon is the catalyst for the escalation of a violent family feud. In rural Arkansas three men were abandoned when they were boys by their drunken father, who cleaned himself up and started another family ahd had four more boys. The three boys' mother teaches them to hate their four half brothers and this family feud heats up after the father dies. After a few angry encounters between the two groups of men, we see one of the second family aim a rifle at a Cottonmouth crawling on the ground when his older brother tells him to stop because he wants to catch the snake, but we never hear why. Then we find out that one of the three brothers' dog is dead, killed by a snake. We learn that a kid found the dog bit on the nose by a snake that was curled up in the dog's water dish, then he found the snake and cut its head off with a shovel. When a friend of the three brothers tells them that the snake was put there by one of the four brothers, the revenge violence and bloodshed begins.
While all of this is not impossible, it's extremely unlikely that it would work. We are asked to believe that you can put a venomous snake in a dog's water dish and it will stay there until the dog comes to the snake and gets bitten. While it's possible a dog would be curious enough and unaware of the danger to investigate the snake, there is no way a snake would just sit there in the bowl after being captured and hauled there in a sack. We're supposed to believe since it's a Cottonmouth which lives and feeds around water that it would prefer to stay in the water rather than quickly crawl away from there as fast as possible which is exactly what would happen. The writer/director of this movie also wrote and directed the movie Mud, which also uses deadly Cottonmouths, but in such a dishonest way that it almost ruined that movie for me.
We don't see any of the snake action that happens after we see the snake crawling on the ground, we only hear people talk about it. The snake is never in the same shot with any of the actors. This makes sense because the snake we see is a real Cottonmouth.