Way back when I was around 19 or 20 friend and I had taken a group of neighborhood kids (10-13 age range) out in the woods and we were telling stories around the campfire. The kids took turns telling stories but they were all the cliche ones that all of them already knew. So I decided to simply make one up on the spot. Which I quickly realized was a mistake because many stories of this kind are like jokes, they hinge on knowing and properly setting up the final punchline.
However it was a story they never heard before so there was no way they could ever guess the ending. And if any of them has spoken up about what they thought might happen I could always just change course and create a new ending. For being made up as I went this story ended up being better than it had my right to be. The kids loved it and my friend asked where I got the story from because he liked it too but had never heard it before. When I told him it was improvised he said "That's really cool that you could make all that up on the fly. It also explains why all your characters were named after characters on Star Trek."
I don't remember much of the story now, but the highlights involved a farmer whose scarecrow had come to life and nobody in town would believe him. Eventually the scarecrow kills the farmer and wears the farmer's skin to go into town pretending to be the farmer. If anyone questioned the farmer/scarecrow about this the scarecrow would come after them and take their skin as well.
