I had a pine log in the creek wink at me, while I was wading upstream just across from it. Pretty sure that was a 'gator, though I've never seen another before or since in that creek.
Earlier this summer I found a 5' long rat snake on the bottom of that same creek, below a bridge, dead. No visible signs of injury to be seen on it. Rat snakes swim, too.
My sisters were stalked by a black panther in our woods once, not long after they heard that same panther kill and eat a deer in the woods just off the driveway. We used to live father back in the woods than we do now, and it was a half a mile walk out to the mailbox every day, or to my uncle's house down by the road. They were walking it at dusk.
My dog drug up a headless rabbit sometime this spring/early summer, and was playing with it like a toy. No idea what took the head, though I'm guessing it was one of the pair of red-tailed hawks that we have in the area. One of those same hawks once spent about ten minutes swooping down harrying my brother's little yapper dog. The thing looks and runs just like a rabbit, and the hawk thought it was lunch.
When I was little I had a small dog that romanced a female fox. He would share his food with her on the back steps every night.
I'm sure I'll think of more. Living where I do, I've seen plenty of weird stuff. I gotta say though, that spiderweb Bear posted is AWESOME.
