Title: Potter's Pets
Protagonist: Harry Potter
Harem Type: Natural
Protagonist involvement: Incidental
AU: Hogwarts start at 18
Summary: During the hunt for the heir of Slytherin, Hermione Granger ingests Polyjuice potion that was tainted with cat hair, only to discover why the books warned not to use another species in the potion; she is transformed into a cat girl; fur, 6 boobs, cat ears, wiskers, claws, a tail, the whole thing. To turn a humiliating situation into a nightmare, the 20-year-old girl soon realizes she isn't turning back.
Worse still, Hermione soon learns that because of her transformation, Hermione is no longer classified as humans but as a magical creature. Fortunately, before someone like Lucius Malfoy can make a claim for ownership Harry is able to get Hermione registered under his name, taking advantage of having saved Hermione from the Troll the previous year to claim a life debt, which would supersede anyone else's machinations trying to acquire custody of Hermione.
But Hermione's case ended up not being an isolated incident, between accidents, cruel pranks, and even a few deliberate acts, a fair few girls end up being transformed into animal/human hybrids, who, after being declassified as humans, end up being registered to Harry in his attempts to make sure they are looked after, particularly since Hermione helps harry uncover his family's wealth, getting him away from the Dursleys.
But how many will it end up being; how many of the female students of Hogwarts will end up becoming Potter's Pets.
Note: In the event someone starts this story before I come back to it, please begin with Hermione's transformation. Also it should be obvious, but for this story we want girls to be either hybrids of humans and animals, or magical creatures of some kind, no ordinary witches here please
Title: The Blessings of a Champion
Protagonist: Harry Potter
Harem Type: Magical
Protagonist involvement: Incidental
AU: Hogwarts begins at age 15
Summary: After Voldemort's return, Hermione Granger quickly realizes that it will ultimately come down to Harry vs Voldemort. Desperate to find a way for her friend, a good wizard but nowhere on Riddle's level, Hermione dives into research on ways to give him a boost.
Soon she discovers a spell called the blessings of a champion; a witch could bind herself to a champion for whom she held love, allowing him to access her magical pool on top of his own. Seeing that more than one witch could bind to a single champion, Hermione, once she arrived back at Hogwarts reached out to find as many girls who loved Harry as she could; including Ginny Weasley, Cho Chang and Luna Lovegood and on Halloween night, they gathered in the Room of Requirement and cast the spell in secret, even from Harry.
Harry immediately showed an improvement in his magic, but soon other things started to happen, strange things:
The first one was any boy (or girl) other than Harry who had previously shown a interest in any of them suddenly lost that interest. This discovery, to the surprise of the girls, was simply academic, as their own interest in anyone other than Harry and each-other, had faded into nothingness.
The Second was that their romantic interest in Harry and each other, grew incredibly and when it was brought up that they couldn't very well all date harry, that's all they wanted to fantasize about.
Third was that harry was suddenly a lot more... free around them, happy to do things like pull them into his lap or casually grope them, and not only did neither he, nor anyone around him see anything wrong with that, but they wouldn't protest, and in fact often encouraged him, and doing whatever he told them.
The Fourth thing was that they started to change; their bodies, clothes, minds. There was no specific theme uniting them, but they were all changing, eventually they'd figure out that they were changing to match Harry's various fetishes.
Realizing it was the spell, the girls looked more into the spell, and realized to their horror that they hadn't just bound themselves to Harry as power boosters, they had bound themselves to him as Sex Slaves. They were changing to suit his tastes, they were magically compelled to obey his every instruction and only have an interest in Harry and each other, everyone else was compelled to see them as Harry's property, even Harry was compelled to view them as his property and treat them as such.
Worse still, there was no known way to rescind the blessing. As they continue to transform, the girls desperately try to find a solution, but will they find one?