Black racers may be what you are thinking of but my pictures are of a chicken snake.
A few years ago we had a drought and all the pasture grass dried up and turned brown. I started feeding round bales of hay in August and continued until the next May.
That Fall one bale I had picked up with the loader of the tractor and started down the farm road towards the pasture. I did not get very far from the barn and I noticed something moving around on the bale.
WTH, was my first thought but then I could see that it was a Black racer trying to find a way to get off the bale. Before I could stop the tractor and set the bale down, it made a flying leap off to the left side of the bale and hit the ground at full speed.
Sure was glad because I did not want it to crawl back into the seat and steering wheel to help me drive......
Yeah, probably that's what I'm thinking about. I'm with Rose though that all snakes dangerous. I would have thought that guy a rattler and wouldn't have stuck around to look at his head and probably have hurt myself:')