(This a Harry Potter AU and in Doctor Who anything can happen so for that this is probably not an AU. Disclaimer, I do not own any of these movies/t.v series. Enjoy)

The Doctor was currently eating some watermelon in the TARDIS and to be honest it was quite good.

The TARDIS was currently trying to find a new and interesting place to visit for her time-lord, because he has been so bored with the Ponds gone. She must also remember that there must be gingers there. No, no, oh no no no, Ye-no, YES! PERFECT! Her Doctor is going to love that place. There are also so many gingers!

But, oh. Well he already behaves like a child, so becoming one again should not be a problem.

….

The Doctor was interrupted from murdering watermelons by the TARDIS making the sound that she wanted him for something. To be honest he did not care that he left a bit of a mess he was just SO bored.

When he arrived in the control room the first thing he noticed was the Egijabtor sitting on a seat. That means that he must change his age, appearance-wise at least. The screen then started having Gallifreyan text flash on it, for normal humans who somehow managed to learn the text it would have gone too fast to read but for the Doctor it was easy.

After reading through the text the Doctor agreed with the TARDIS that it would be interesting. So interesting that becoming a Gallifreyan 12 year-old was not a big deal. Unfortunately he could not become a human 12 year-old without losing his memories. So he had to deal with hiding his Gallifreyan body parts, but no matter.

After having a session with the Egijabtor, he had the TARDIS create suitable clothes to fit him and the uniform requirements. When he went to look in the mirror he saw this; a 1 meter and 33cm, (4 feet 4) boy with big, orange-yellow (the colour of regeneration energy) eyes with slitted pupils and fluffy, dark brown hair pointing in all the directions of the compass. He (a bit to his disappointment) had pale skin with a dab of freckles sprayed on his face. The clothes were the school uniform but since he had no house, the colours were not present.

And sticking from his hair were the two 10 cm (4 in), black horns that came with pre-pubescent pure-blooded Gallifreyans. (It's a fanfic, I can do whatever I want.) They usually fall out the end of gallifreyan puberty and since he is in terms of earth, then he far off from that. The Doctor spots a wool hat and puts it on. The horns are not visible under the orange and yellow knitting and it looks cool. He does have other non-human features but they are hidden beneath his clothing. (Don't you even think about it you pervs, not those features)

"Not too bad a look for this form, though the pale skin is not cool at all, right Sexy?" He asked noticing how higher-pitched his voice was. The TARDIS made a sound that was similar to a mother sighing in response to her child being dressed up in cute costumes.

"Right remind me never to make you a grandmother." The TARDIS sqaucked in protest of that.

"Now all I need are some materials and I'm off" The TARDIS made a depressed noise at that.

"Don't worry I'll only be gone for less than a year." A beeping interrupted their farewell. It came from several slots that pushed out books and various powders for the school that he would go at. At the far left slot came out a wooden stick. He took it and swished it. Bright green sparks came out.

"Ah, so this how human's use magic? It's just using the body's own psychic energy and manipulating it to affect their surroundings. I mastered this at the end of the first day in the Timelord Academy." The TARDIS hummed in agreement.

"Well I have all the goodies that I need, so goodbye for now you sexy thing." The Doctor said grabbing his stuff and stuffing them in his bigger-on-the-inside-than-on-the-outside pockets.

The Doctor pushed open the TARDIS doors and appeared near a train with students boarding around the corner. The TARDIS then flew away, to stand, invisible on the edge of the school.

A girl with brown hair was yelling, "I'm finally going to Hogwarts!"

…...

Now a brief biological description of Gallifrayans would be helpful at this point. Now Gallifray was originally a tropical planet and the ancestors of Gallifrayans were cat/bull creatures, called Gallibeans, that ate everything. However soon rainforests began to dry up and that formed plains. The Gallibeans were forced to adapt to a flatter world. Then they pretty much followed the same evolutional tree as how humans did. But Gallifrayans were smarter and still had some parts of their ancestors but only before the end of puberty, then they would be identical to humans on the outside. Pure-bloods had the most.

Before puberty pure-bloods like the Doctor would have horns that grew to about 25 cms at most (10 in), slitted pupils, longer and harder fangs and pointer ears. Their eyes would be any shade of yellow of orange, this later colours into a more 'natural' colour.(Once again this is fanfic and I can create all sorts of new stuff and this is not all that extreme guys.) This all disappears by puberty.

All Gallifrayans also have higher senses and abilities than humans. More speed and stamina, more strength and more endurance. Higher levels of 'magic', as well as able to sense it and take it from things or people around them, more powerful senses such as hearing and taste, and finally the ability to sense heat. That is all a need to know stuff.

….

Now, the Doctor has had the TARDIS bots send a letter to the principal of Hogwarts saying that he was attending the second year but has not been sorted, because 'he was a late bloomer' and that already knows the spells and the such for 1st years.

The TARDIS said his name was Theta Sigma, a name he used a few times as a cover name, and that is was signed by 'Tardis Sigma', he was sure to talk about that when they saw next.

He was sitting alone in a room already reading a book for the school when three kids walked in and sat down with their stuff, not noticing him due to him sitting in the corner. Sitting in the corner looked cool.

One was a ginger boy with even more freckles than himself, the only girl of the trio was a smart looking girl with a lion's mane of brown hair and the second boy had black hair with glasses and a scar on his forehead. It was giving out slight psychic waves, which means it was done by a 'spell.' After talking for a good few hours and still not noticing him, a woman called,

"Sweeties on the trolley!" After the children, which the Doctor knew the names of now,(if you don't then why are you here?) bought the sweets, the girl spotted his hat sticking from behind the door where he was sitting and almost yelled.

"How long were you here?!" The boys now seeing him had looks of shock on their faces.

"I was here before you bunch came in here." The Doctor responded confidently.

POV The trio

"Did you use a cloaking spell?" Hermonie asked, shocked but also a little bit curious how this small boy was here without them seeing of hearing him.

The boy looked as thin as a twig and about as small. He had chocolate-brown hair with a yellow and orange, woolen hat sitting clumsily on top of it. His clothes were (surprisingly) made of an expensive material, with not a tie as it is normally but a bow-tie, his skin was pale with a handful of freckles. His eyes were one of the most amazing things she had seen. Large with slitted pupils, their colour was similar to honey but far more glowing. Those eyes, they looked like have seen more than they should have, know more than they should have, those eyes looked innocent and kind, but Harry noted, with a glint of something else there.

"No, just used my ninja skills." The trio blinked in confusion. Neither of them knew what a ninja was. Ron changed the subject.

"What did you hear?"

"Dobby, birthdays, arriving to the train by the skin of your teeth, may I ask what caused that?" The boy asked. He suddenly slapped his head, dropping his book on the ground.

"Sorry I was terribly rude, I am the D- Theta Sigma." Harry could swear he was about to say something else but a sneering voice interrupted before he could voice his reply.

"Sigma? What family is that?' There leaning on the door was none other than Draco Malfoy, smirking his arrogant smile. Theta turned and smiled and waved to him.

"Hello to you too! Who might you be?" Theta asked. Malfoy for a second looked surprised but replied.

"I am Draco Malfoy, a pure-blood unlike Granger over there." Theta's expression darkened for a second but changed back to his innocent farce. Malfoy was oblivious to it.

"May I ask, what is so important about blood purity?" Theta asked standing up to his small height. Malfoy began moving towards Theta.

"Pure-bloods like me are better than mud-bloods and blood-traitors other there. Are you like them?" Draco asked towering over Theta. Instead of cowering down like most people, Theta or the Doctor however you call him, just smiled. It wasn't a smile of a child; it was a smile of an adult who would see a fly that had annoyed them for hours about to get squashed.

"By your definition of the word I am not, but by other people's definition I am. And just for your information, you aren't actually a pure blood. Your Great Grandfather, Duke Wesly Malfoy, he was muggle-born." With that the small boy walked out of train room, leaving behind a stunned Golden Trio and a speechless Malfoy.

After 2 or so minutes of still silence Malfoy waddled out of the room.

….

After trying to find a new room for about 10 minutes, the Doctor found a room occupied by nothing else but two ferrets. They were strange looking. They were a fire-red colour with yellow and orange specks on the fur, they had a black mask, black feet, a black tail and they had sparkling red eyes. They were as well extremely fuzzy.

In Gallifray they were called Perpats, creatures that flocked toward beings of great power and in exchange for some of the energy would protect and serve the person of power. Back in the days before the war, they were common as cats on Gallifray. But due to the war, most of them died. About a handful of them lived on, and due to lack of people to have energy of, they became sick and gradually died out.

Except for the couple in front of him, they were probably a mating pair. They were staring at him with their adorable eyes, pleading for permission to make a contract with him.

The Doctor nodded and sat down next to them. You could see the utter joy in their eyes at being allowed to take energy and finally feel better.

Placing one finger on each of their noses, the Doctor probed their minds to find their names. One was Daisha (the girl) and the other was Johan (the boy), upon saying their names the trio where now in a contract. On Daisha's front left paw and on Johan's right one was placed the Doctor's symbol, a blue rectangle with an orange spiral in the middle.

In exchange for their obedience and protection, the Perpats each got to feed off some of the Doctor's energy, as well as knowing the Doctor's true name.

…

So the Doctor sat, with both Perpats sleeping at his sides, and he was reading a post graduate book for the ninth time, simply to laugh at some of the things in the book. He already read all the books for this term as well as for the rest of the years. The books written by a Lockhart fellow scared him.

How could one man have so much arrogance and naught to justify it? Sure the Master had arrogance by the boatload but at least it his ability was genuine. Lockhart seemed like a man with plenty bark and none what so ever bite.

The train slowed down them stopped.

A man outside was bellowing for first years to go to him.

Rubius Hagred, he supposed. Gently waking up the furry creatures at his sides, he picked up his things, and stepped out.

(DONE! Took me forever, do what me to continue this or not? Cause this could be fun but I have so many other things to update, so the word is yours!)