I read this book back in middle school, but cannot remember the title. It was a great story, but I can't seem to find it.
The book begins with a woman falsely accused of witchcraft by her neighbor. She is found guilty and is sentenced to be made into an offering for the dragon.
When the dragon finds her, she throws stones at it in a rage. The dragon finds her reaction curious and shapeshifts into a man who agrees to help her seek revenge on her accuser.
Dragon's Bait (1992) by Vivian Vande Velde.
From Goodreads:
Fifteen-year-old Alys is not a witch. But that doesn't matter—the villagers think she is and have staked her out on a hillside as a sacrifice to the local dragon. It's late, it's cold, and it's raining, and Alys can think of only one thing—revenge. But first she's got to escape, and even if she does, how can one girl possibly take on an entire town alone? Then the dragon arrives—a dragon that could quite possibly be the perfect ally.
The reviews mention the dragon (Selendrile) being able to change into human form.
Found with the Google query fantasy novel accused witchcraft sacrifice dragon site:goodreads.com/book.
