Okay, so, I have no leg to stand on when it comes to history, but I have encountered many a fox in my childhood and have plenty of neighbors with farms who have plenty to say about foxes, so I may shed some light on why every single human who saw a fox declared it a bastard.
It has to do with two things:
1) Foxes are notorious thieves, because why would you invest energy into running something down and then fighting it to death for dinner, if you can take someone else’s dinner with much less effort? So foxes steal any livestock they can, because to them human farms are like an all you can eat buffet. All of the prey animals are corralled in, fat and much slower than those in the woods. It’s practically an invitation!
This has, as you can imagine, rather vexed every single farmer in the history of farming. Probably longer. And the more used to humans they are, the more audacious foxes are. Which brings us to the next point.
2) Foxes laugh. Go ahead, google a video. What does it sound like? That’s right, suspiciously like laughter. Suspiciously like mocking laughter.
It’s not actually laughter, or at least not in the way humans use that word, but to an average human who has not been poisoned by the horrors of biological sciences, it sure sounds like laughter.
So imagine this: you’re a farmer. You have chickens that you care for and care about. You want them fat and happy to lay you eggs and one day become dinner. They are your chickens, and you guard them jealously.
Enter something red and furry and hungry. It burrows under your defenses and sends your chickens into a frenzy. You run out to defend them but the damage has already been done. There are blood and feathers everywhere and there, over the hill and just out of your reach, is the blasted red furry thing, mouth full of your beloved chickens, and it only lets them down on the ground long enough to laugh at you before running away with them.
Damn right you are going to tell all of your buddies what a bastard that fox was, and they are going to nod and agree and lament about all the other red bastards that have stolen their chickens.
And when your children ask you why you hate those bastardous foxes so much, you are going to sit them down and tell them all about it.
And that is how foxes have gained their reputation as Complete Assholes all around the world. Because humans laid out a buffet, and then got mad foxes helped themselves to it.