Sometime in the '80s, I was at the house of a friend of my parents who had a huge library of SF/F paperbacks. Like the kid in the candy store, I grabbed one off the shelf and was rooted to the spot until I had to be dragged away for dinner. Being just a kid, I didn't write down the title and author then and there, but the beginning of the story stuck with me:
Protagonist is born a magician, in a world where magicians are rare but known and not respected. Magicians all have a characteristic animal form: protagonist's ambiguous mentor/nemesis figure is a bear, for example. Protagonist is engaged to be married (above his station, I think) and wants to suppress his magical side -- but all of that collapses miserably when he involuntarily turns into his characteristic animal during the wedding procession. The protagonist's animal form is something made up for the book, but large, ungainly, ugly, and usually thought of as vicious.
I hope I've provided enough detail to jog someone's memory.