Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
A theme of fear and hatred of snakes runs throughout this film. In the first few minutes we a boy throw a large rock into a puddle full of writhing black snakes (I can't tell if they're Black Racers or maybe Indigo snakes) for no apparent reason other than he thinks all snakes must die, covering two ridiculous snake movie myths - that they swarm in groups (especially in the water) and that you have to kill every snake you see even if they aren't a threat. The boy later tells Mud that he hates snakes and Mud says "That's 'cause God put 'em here for us to fear. We knew to be afraid of snakes long before we even got in to this world." He throws a rope to the boy and tells him to put it around his bed because a snake won't cross a braided rope. (Another ridiculous snake myth.) Mud tells the boys that he was bitten under the armpit by a cottonmouth when he was 10 years old while swimming in a river. He has a huge snake tattoo from his chest around his back and around his arm to the back of his hand which he says is a reminder: "Don't get bit." Later we see a man shooting a water snake from the roof of his houseboat with a rifle, again, for no good reason.
With all of that set up it was obvious that someone was going to get snake bit in this movie and sure enough, one of the boys falls into that same puddle full of snakes we saw earlier. Those snakes must never leave their wallow. (Again, most of them look like racers or Indigo snakes racers or maybe black rat snakes with some kingsnakes thrown in for variety. It's hard to say, and some might even be CGI snakes.) Mud jumps in to save him (despite the fact that he said earlier he would die if he got bitten again because anti-venin only works one time (another myth) and then uses a marking pen to mark the bite location and to keep track of the spread of the venom as he rushes the boy to the hospital. This is a surprisingly smart depiction of dealing with snakebite for a film that is way out of touch with reality regarding snakes and their behavior. They would claim poetic license I suppose, or say that they are using snakes because of the bible, and tell me that if I want realism I can go watch a documentary. Regardless of poetic license, this is another film with lazy writers who choose to spread malicious lies about snakes just for a convenient, unoriginal plot device. Too bad, because otherwise this would have been a really good film.