Untitled Sighting

It was 1:30 am, myself and two friends were cave hunting at Crosley Wildlife Refuge, just walking through the woods. We had walked about a 1/2 a mile off a road, following a small stream. I commented to the other two that there was a strong smell of urine, they both agreed. We came to a small log jam, and stopped walking. I was looking around, on the bank, I thought that I heard something, I did, not only that but I saw something too.  I'm not to sure what it was. It was about 8 1/2 to 9 feet tall, it's head was about as big as a cows head, it had very large green eyes, possibly from my headlamp its eyes were about the size of silver dollars, I could see its ears about 3 inches back past its eyes. One of my other friends saw it. I picked up a rock and threw it at the animal, it just walked away and stopped. We all at that point started to walk fast back to where we parked the truck, all the while throwing rocks at it. It followed us, but never came closer than about 30 feet.  As far as a better discription, It was dark out, I guess it might have been dark brown or black in color, and a very strong smell of urine came right before we saw it.