Books, for adults, that has an animal as the main character, that teaches life lessons and forces self-reflection.

I'm looking for books that involve an animal (anthropomorphic or not) as the main character, and that will end up making me do some self-reflecting on my life, think about conflicts and struggles that adults deal with, and maybe make me teary eyed. More grownup/adult versions of the books we read as children where animals were the focus and taught us to be good people, basically. But as an adult, I still want that nostalgic feel of reading a fiction book but being able to connect as an adult dealing with a different set of life's challenges. IDK if any of that makes sense or a book like that exists lol