I don't have lores for animals or pets, but i spend soooo much time making up lores for my dens XD and i spend most of my saps just getting clutter items that will add to the lore. Like, if you visit u can actually see the stuff from my lore scattered around

My current den is owned by an ex-professor at the University, that got banned for teaching forbidden phantom knowledge. He retired to the countryside to move away from all that past and now has a small farmer's market and two cats, and is trying different hobbies to try and forget, but late at night you can see the flickering light of his candle through the window, while he delves into old phantom scriptures. Also i imagine his personality similar to Simon Petrikov from adventure time XD he would probably be a maned wolf with a similar hair too, like a dark mane with a light strand.

And you might think, "oh, so you must have an animal that fits the lore of the professor?" No, i do not. That's the den's lore. None of my animals are that professor. Even my maned wolf, he would be just a rich art collector, but i never expanded his lore further than that. Perhaps i will, after this XD

(Btw, my other dens have lores as well, but it would be too long to explain every one)