Pig Hunt

In the opening scene, with a man running for his life through the forest, obviously in a panic he hides behind a tree, trying to spot what was following him. As he calms down, something comes up from behind him, throwing him up into the air and back down again. The man screams as something begins eating him, and as the man dies, the camera turns to a pair of dog tags that are slowly overtaken by a small river of blood.In San Francisco, John Hickman (Travis Aaron Wade) and his girlfriend Brooks (Tina Huang) are a pair of residents who invite their friends; tough guy and military man Ben (Howard Johnson Jr.), his close friend Wayne (Rajiv Shah), as well as the naive and weak-willed Quincy (Trevor Bullock) and his dog Wolfgang, to a backwood redneck community for a weekend of hunting, drinking and fun and camping near John's uncle's home. Enroute, they stop at a gas station for directions and encounter a van of hippie women and their male leader who run a commune in the woods nearby. After obtaining some supplies and directions, they make their way to the abandoned cabin and camp outside.The next morning, they encounter Jake (Jason Foster) and Ricky (Nick Tagas) old friends of John's who are interested in joining them on a wild hog hunt. Quincy, who is eager to get to know them is obviously inexperienced in any sort of outdoor activities, and Jake accuses Wolfgang of being a 'pet' not a 'dog' seeming equally oblivious to hunting as well.As the group makes their trip through the woods, they encounter an area called the Big Wallow, where boars are known for hanging out and using a horn as a lure, they manage to convene several pigs on their location. One of them rams into Wayne's leg at full charge giving him a compound fracture in his kneecap and incapacitating him. Wolfgang goes charging after the boars while Brooks shows off her marksmanship talents and kills one of them.While looking for a way to carry Wayne back to the cabin, Quincy encounters a large stash of marijuana plant in a forest clearing and leads the others to it, leaving Brooks with Wayne. A conflict emerges when John objects to Jake and Ricky taking the plants for profit as they appeared to have been cultured, and an ensuing argument forces Ben to kill Ricky who was ready to kill John. Jake flees to tell his inbred clan, and the others return to Wayne and Brooks, while Quincy and Ben start making their way back to the cabin while Brooks and John leave Wayne to seek help and head for town. Shortly after their departure, Wayne is attacked by something and manages to fire off a single round. Brooks and John circle back and find him missing as well as Ricky's body.Meanwhile, Ben and Quincy make their way back to the cabin. They find Wolfgang's mutilated body, and determine he was killed by the rednecks. Ricky and Jake's clan make their appearance, Ben manages to kill his pursuer and escape, but Quincy is knocked out of the jeep he was attempting to escape in, and is executed by the bloodthirsty rednecks in a fashion of any suffering animal; with a single gunshot wound to the back of the head.The redneck clan members then go after the surviving hunting party where they are ambushed and killed in passing by Brooks as she and John make their way to the main road, only to be pursued themselves by the clan. The wounded Ben makes his way and finds the commune where he is led into an enormous pit. He encounters Wayne who says that something has been eating him, Ben turns to see something approaching him, but his fate is not shown.Brooks and John run into the same hippie they had seen earlier who slays two of the redneck hunters and leads the pair of them back to the commune. When John questions why Ben's equipment is there, but not Ben himself is not, they force him into a cell while the leader takes Brooks out into the pit. They encounter "Pigzilla" an enormous, three-ton and a half boar who is finishing the remains of one of the redneck clan. Jake makes his way to the commune and forces himself into John's cell, as Jake prepares to kill him, one of the commune women attack him, stabbing him in the eye with her boar's tooth necklace before she gets shot. Jake dies from his wounds while the hippie leader tries to feed Brooks to the boar. She forces him to move in front, causing the boar to turn its gaze on him, and despite his best efforts, he has his intestines ripped out by the creature. John forces his way from the cell and using a crossbow, fires an arrow up under the boar's jaw. He uses force and lodges the arrow up into the boar's brain, killing it. As the pair recover from these events, they fail to notice one of the redneck clan's children watching in anger as John and Brooks make their escape from the commune.

Question: What was slowly overtaken by a small river of blood?
Answer: Dog tags