Part 1 (Before we saw the ending)--
It is entirely possible for dogs to sense danger. Being so, the dog, Chance, could've ran from Steven to see what was going on or maybe because he wanted to go by the water or have fun in the woods. Whatever the reason, I believe that there is something there. But it's not a cougar. Humans can be 300 pounds, and maybe it was a homeless person, who doesn't have people skills and cannot talk (explains the growling noises at the end). It didn't really sat anything about the Cougar being bad, however in the background that we are given, the person says that there are more "pets and children to pick from", and that could have so many meanings. Maybe the person is lonely and wants to chose a friend or pet, or maybe the homeless person wants to hurt them. Either way, the person would attack him, and he would not return home, and the dog would also be gone. The person would not be show himself... only to people/animals who find him.
This is like the story of Wrong Turn, because the creatures living in the woods do not go searching for food that is out of their territory. Just like the supposedly homeless man in Steven's story. They attack people who come near them. The mutant creatures would eat the humans, and so obviously they would not return home. They were first attacked of course, just like I predict will happen to Steven.
Part 2 (After we saw the ending)--
Although we did not see exactly what it was, we did see its vision, and its vision was not human whatsoever. They also did not say whether or not Steven made it out alive with his dog. But I seriously doubt he did. It leaves you to your imagination and I believe that he was only overreacting, and its a lesson for people who search for trouble, such as Steven (although he didn't know it) and Mrs. Littky (because her imagination can go wild considering she can't see all that well). He did get attacked, which I was right about however.
