This fic is told from Crookshank's perspective, one which I think would care little for names, so I got a bit creative when trying not to use names :)
Crookshanks padded slowly from the Girl's Dormitories, his bushy tail waving to and fro as he went. Out of the portrait hole, down the steps and through a window and into the grounds. The lights of various stars shone from the midnight sky as Crookshanks moved along the cold grass, a preferable change to the colder, harder stones of the castle his mistress resided in.
The other animals in the castle marvelled at their surroundings, but Crookshanks was far smarter, he knew Hermione was no princess, though for rescuing him from that awful shop, in his opinion she should be. He found the castle boring, the people more so and the animals - Merlin if he heard those blasted owls complain one more time about their transportation in cages, Crookshanks swore he would turn the Owlrey into his own personal playground, THEN they would have reason to complain.
This train of thought lead Crookshanks to his current goal; the quiet of the night. The other creatures in the castle didn't enjoy straying at night, preferring to keep a vigil near their masters. Even the owls would rather swoop around their masters dormitory windows at night, rather than hunt - that was for daytime, when the bigger humans could protect their masters. Crookshanks knew his mistress would be fine, he had heard muchof the human tongue in his years and whenever Hermione came into conversation, 'clever' often followed. Crookshanks knew this was a good thing, and so as he weaved his way towards the Forbidden Forest, Crookshanks paid no heed to thoughts of what Hermione would think if he were to go missing, merely scoffing at the thought of either getting lost (as if!) or becoming deterred by the powerful creatures within the forest (the wolf that was also a man worried him, though not enough to scare him away).
The soft noises of the night comforted Crookshaks, so different to the Menagerie he had been living in for so long. Replacing the irritating squawks and squeaks was a gentle whoosh of cool air and a soft silence that made Crookshanks content to lie and sleep on the forest floor, rather than become more and more agitated by constant noise that people would begin to assume him rabid. Where the stench of other animal faeces used to assault his senses, out here there was almost a quiet harmony, a natural diffusion of scents by the growing foliage around him. Rather than feeling constantly under threat, Crookshanks was calm. He didn't fear the night being free, he feared being caged up again or worse cast aside, but he knew Hermione better than that. She understood him and he would stand by her for it - even if that meant trying to help that red haired buffoon, because there was no way that rat-shaped thing that went around with him was really a rat. It smelled wrong. In fact, Crookshanks could smell something very similar right now-
Whipping around, hackles raised and teeth bared in a hissing snarl, Crookshanks came to face another animal-that-wasn't, this time in the form of a dog. The dog-that-wasn't-a-dog barked but Crookshanks held firm, he was not about to be bullied by a fake creature. Charging forward, Crookshanks propelled himself from the ground and barrelled into the skinny creature, weakened from starvation from the looks of it. Crookshanks scratched, bit and sank his claws into the creature, catching it completely off-guard. It escaped his hold and span, tilting its head like a confused human.
Crookshanks hissed again in warning and the creature stepped back slightly before slowly moving a couple of paces closer, and stretching out its front paws, head following until it rested on the ground, looking up intently and Crookshanks. Out of curiosity, Crookshanks padded forward until he was standing before the -not-quite-a-dog, slightly to the side. The creature rolled, tilting its head back to expose its throat to Crookshanks. No threat, it was saying. Crookshanks was inclined to believe it, though the creature was definitely not an animal.
The thing must have noticed Crookshanks still raised hackles - a sign that he still didn't trust - and quickly scanned around them, ensuring they were quite alone, before silently morphing.
Crookshanks gave a start and made to run, however, a slightly familiar scent caught his nose, human. In confusion, Crookshanks remained rooted to the spot as he watched what once looked like a dog now look like a human. Crookshanks shook slightly, his slit-pupil eyes wide - just what was this creature. His already bushy hairs stood even further on end as adrenalin made to force his body into a flight reaction-
Or he would have had the dog-now-man not gruffy called, "Cat, wait." Taking a closer look, Crookshanks saw the dog-man looked terrible, all sunken, pale and shaggy. His body didn't look strong enough to cause Crookshanks much harm, though that didn't mean he wasn't going to be cautious.
The dog-man once again changed back into its animal form and offered its neck to Crookshanks. It struggled with animal-tongue and instead padded at a piece of paper it must have left out in human form. It was a picture of that rat-like thing and the boy his mistress liked. Crookshanks hissed at the picture, the dog-that-was-really-a-man seemed to agree and gestured between the picture of the rat-thing and itself.
Did it want the rat-thing? Crookshanks thought so and flicked out a claw, carefully carving the section that held the rat-creature from the page and pushing it to the dog-that-wasn't-a-dog. It nodded its head, barking in a happy way that suggested Crookshanks had guessed right.
That was fine by Crookshanks, if the dog-that-wasn't wanted the rat-that-wasn't, it could have the pitiful creature. Crookshanks hated the damned thing anyway. Besides, he didn't want that thing anywhere near his mistress. For Hermione, he would risk himself to destroy that not-rat.