Personally I have no knowledge or opinion as to what type of snake it was or whether it was poisonous or not. It seems you have a lot of opinions but no definitive answer. If you are really interested in knowing what it was, you might want to contact your local agricultural extension or your nearest university with a good biology department.
You evidently felt it enough of a threat to you and your animals to kill it before seeking any advice. And I’m not implying that was bad thing to do or that you were wrong for doing so. If I’d run across that snake near my house, my first reaction would be to kill it too.
But we often kill off predators without considering the consequences. Sure, the snake might have been dangerous, not something you’d want in your back yard or that I’d want in mine, but you and your pets were probably not its primary food source.
So what was: mice, rates, moles or other such creatures you might now have to call an exterminator to be rid of?
We kill off predators for doing what predators do and then end up overrun by their prey, which often end up being an even bigger nuisance.
The pictures sort of indicate that the snake was moving away from you, trying to avoid you, as most snakes tend to do and that you perused it, it got defensive and then you killed it with a shovel. Again, not saying that was wrong but looking at it from the snake’s perspective, you were the aggressor.
I would not want poisonous snakes living in my back yard close to my house, but a few non-poisonous snakes that kill off vermin like mice and rats? I’d consider them just part of nature’s plan and my friends. Just saying….
Humble clearly did the right thing here. He DID NOT waste any precious ammo on the invading reptile. He killed using only hand tools (weapons), just like the indigenous tribes.
It’s to be celebrated around camp fires for generations to come. “Dances with shovels” will be painted as rock art for centuries.
I'd imagine the cats do pretty well at the "exterminator" job. Small dogs, like a dachshund, may be quite effective as well, even chasing rodents into their dens.
We had a 1/2 Australian Shepard, who would corner and kill squirrels, which takes smarts as well as good reflexes. The first one I watched her stalk. Every time the squirrel would raise its head, she'd freeze, and the squirrel would go back to its acorns. By the time the squirrel realized he was being stalked, the dog had worked her way between the squirrel and his escape tree. So he went the other way, but the tree over there had metal flashing about 4 feet off the ground, put there to keep his kind out of that tree. Worked too. The dog and the squirrel went 'round and 'round about 3 times, and then the dog finally managed to time her leap and snap just right, and the squirrels neck or back was broken. Devastated my young daughter, who also watched the whole thing. Until that is my dad, whose house and yard it was, explained that she was just doing what her kind of dog was meant to do. Latter she trained a larger/younger dog to be the blocker, while she went after the squirrels, in her own yard. She just hated the way the tree rats would sit on the fence and chatter mockingly. She got her revenge, and more than once too.
HG is lucky honestly - cotton mouths can be aggressive, and actually pursue any percieved threat