A long story/fanfiction about a young man who meets a mysterious woman with strange powers on his way to visit an old location from his childhood. Which turns his trip into something he could never have imagined.
Ch. 1
http://www.furaffinity.net/view/14641989/
Ch. 2
http://www.furaffinity.net/view/14642002/
Ch. 3
http://www.furaffinity.net/view/14642017/ She grows horns at the end of this one.
Ch. 4
http://www.furaffinity.net/view/14642028/ The Full TF. That happens during their sex.
Ch. 5
http://www.furaffinity.net/view/14642046/
Ch. 6
http://www.furaffinity.net/view/16135934/
Ch. 7
http://www.furaffinity.net/view/16613533/
Ch. 8
http://www.furaffinity.net/view/17716443/
Ch. 9
http://www.furaffinity.net/view/17716471/
You may be wondering what a Draconequus is. This is what she turns into at the end of chapter 4 and is her ultimate true form for the rest of the story.
Anyway a Draconequus actually is what a character from MLP:FIM is called and that character's name is Discord. He's basically a selfish and jerkish version of Disney's Genie because he and his kind (maybe) are actually Spirits of Chaos. Erica in the story becomes a female version of him that is normally called Eris, but rather than just become a cuter and more feminine version of Discord. The author Sharkrags gives her a much more original and unique form that is pictured above. He even made a TF sequence of her and her more unique looks.
1.
http://www.furaffinity.net/view/25592608/
2.
http://www.furaffinity.net/view/25592637/
3.
http://www.furaffinity.net/view/25592665/
4.
http://www.furaffinity.net/view/25592697/
5.
http://www.furaffinity.net/view/25592735/
Along with her fantastic look, there is a more unique story just for her and how she learns about her powers and who she really is and wants to be, while helping her new boyfriend figure out the same things.
I forgot to mention the reason why I wrote this as TF-Romance Story as it fulfills the basic requirement. A shapeshifter or an unwilling shapeshifter falls in love with someone who isn't one. The reason I didn't put this in the thread proper is because the shapeshifter in question of this story doesn't become an anthro, as they become more like semi-feral magical creature rather than an animal.
Edit: Well, what a way to find out that these kinds of links don't work for Non-FA Users. I thought I had found a way to bypass that, but I guess I was wrong.