I was out in the woods with a couple of friends shooting airsoft rifles on each other (we do it in the summer when the hunt is off) when my friend accidently scares up a doe, who runs straight at me, not seeing me being all ghillied up and sitting still. At that speed, those things sure are large! I threw myself to the side and found myself wishing for a whole other type of rifle.
About ten or twelve years ago I was out with my family on a weekend canoe trip. We followed a small river that went pretty deep into the forest, where we really didn't expect any kind of civilisation. About 60 feet up in the air we see a large white bird strung up on a Y-formed branch. First we thought it was a prank, that someone had placed a rubber bird there as a prank, but as we paddled closer we saw that it was a real animal. It was too far up to say for certain, but it was probably a swan that had flown into the tree and hung himself.