It can be anything from “they ride this creature to transport” to “it’s their familiar, they have a connection”. Idrc, as long as the relationship it’s important to the story and heavily featured.
Bonus points if there’s different type of creatures and an actual chance to actually choose your own partner ala Pokemon.
Ideally I’m in search of adult or YA books but if it fits I’m ok even with middle grade books.
by LOONAception