Does anyone have any ideas?
As a cat, Draco was not to be borne. Not surprisingly, he found he didn't mind being a cat. Too much.
Nevertheless, Draco was a house cat, and if you scratched him just the right way, he'd curl up in a little comma-curl and start purring more loudly than he'd hissed. This was a fact he did his best to suppress, but it was no good-- he knew as soon as the Right Person petted him, especially if it involved the soft fur lining his tummy, it was all over. That was why Draco was glad he had claws.
In fact, it was fun to have claws and teeth especially when those uncouth Gryffindors wouldn't hex a darling specimen like himself. Plus, he could spy on anyone he wanted, if he was at all careful. Who would suspect a cat... well, besides McGonagall?
All in all, being cursed by that cow Bulstrode turned out to be helpful for up-skirt viewing purposes.
Other cats didn't like him too much, and there were too many for his liking about, too, which made him feel almost less than special, but it was all right because Parkinson let him ride on her shoulders like the princely being he was, and fed him kippers right out of those over-soft pink-tipped fingers. He felt properly adored for once.
Potter was -right there- at dinner, maddeningly refusing to look over to notice Draco's absence.
Making a low rumbling sound in his chest, Draco leaped nimbly from the table, ignoring Parkinson's soft calls, and made his way under the Gryffindor one, finding Potter's legs by smell. The urge to scratch was almost overwhelming, but he could wait. He wasn't a Slytherin cat for nothing.
He stole a few bits of fish to pass the time, and then he followed Potter home in a stately manner.
When Potter was finally alone in their blindingly red Common Room, Draco pounced.
As per plan, he scratched quite a lot, hissing all the way. And he naturally went for the face-- claws out, jaws wide open, tail straight up.
He got a good five deep scratches in, leaping bravely at Harry's glasses while they were still on his face, but of course Harry was human, and the battle between human and cat usually ends quite simply: in a few scratches, but eventual purring.
Harry blinked rather owlishly, but the cat (who was Draco, but how was Harry to know?) offered no answers, and instead kept hissing while being held by the scruff of his neck.
"Where did -you- come from?" Harry said, biting his lip. He realized he was most likely one of the many cats kept as pets by Gryffindors-- it wasn't as if Harry knew them all. He had better things to do than keep track of people's cats. "Someone must be looking for you." But as it happened, Harry didn't speak cat as well as he spoke snake.
Draco hissed some more, and Harry laughed lightly. "Not the most friendly fellow, are you?" At this, Draco's claws extended, and he started swaying back and forth vigorously in Harry's grip. "If I let you down, will you behave?" Draco's tail twitched violently in outrage. "No, huh." Harry sighed. "Too bad."
Harry thought he was not a particularly pretty cat. The poor thing had almost no fur, though he was all white with grey-tipped ears and paws and huge, round grey eyes. The insides of his ears were very pink, with tiny white tufts sticking out brazenly. Of course, Harry was not impressed.
"You are a very bad cat," Harry said sternly. "Admit it."