Petunia had known the baby that had been left on her doorstep was adopted. Lily had told her as much when she'd visited her at her home for the first and last time shortly after she'd acquired the creature with its messy black hair and green eyes that weren't Lily's eyes. When it had turned up on her doorstep sans Lily over a year later, it had been wearing a Medic Alert tag that listed a number of allergies which had been the first indication of the difficulties she'd have to endure for the foreseeable future.
She could've said no, often thought she should've said no back during the beginning. There had been times that she thought that she should've called the authorities and handed it to them. But, Lily had gone through the trouble of sacrificing her life for the animal, and - according to the letter that had been left with it by an idiot wizard who apparently hadn't realized it wasn't actually Lily's offspring - it would come with protection against Lily's kind.
Her first indication that something was up, and that the child wasn't was it seemed at first glance was that the child was cold. Not exactly cold cold, but far cooler than normal. Even when she'd bundled it in warm clothing and wrapped it in an electric blanket in order to warm it up. She'd initially chalked it up to the fact that the baby had been sitting on her porch for hours. She changed her mind that evening when she'd made a bed for it in the cupboard under the stairs, put it in, and found it looking at her with a pair of catlike eyes that flashed at her in the dark the way a feline's would.
The next day, she took it to a doctor and got a stunned diagnosis of "not human". The day after that, she took it to a vet.
"He's clearly a reptile of some sort." the veterinarian said after an hour's examination. An examination which had started out as the veterinarian's way of humoring the "crazy lady", and continued as the shocked and incredulous vet came to the same conclusion as the doctor.
It figures that Lily would get an exotic pet of some sort and treat it like it was family. Petunia thought as she carried the animal that she'd inherited from her sister home along with a list of instructions for how to take care of a reptile which may or may not be carnivorous. Knowing that she didn't have to treat it like people took a load off her mind and a weight off her shoulders.
The cupboard under the stairs was an obviously unsuitable place to keep a reptile considering how dark and poorly ventilated it was, so Vernon had spent the entire weekend following the veterinary appointment building a special enclosure for it in the sitting-room.
"Always did want a lizard." Vernon said as he lit the warming light that he'd picked up at the pet store and set Harry in his new cage which also contained reptile bark, some fake plants, and a food and water dish.
"Silly little thing." Vernon said with a chuckle a minute later as Harry tried to eat some of the bark only to realize he didn't like the taste and spat it out.
Careful experimentation with the reptile's diet had revealed that a feeding schedule of once a day was appropriate, and that the creature that looked like a little boy would eat fruits, vegetables, crickets, and mealworms but shied away from raw meat and made distressed sounds when he caught sight of the frozen rat that Vernon had brought home from the pet store, nearly causing Petunia to be ill when she'd caught sight of it herself.
Far from being silent like most reptiles, Harry was quite vocal. Aside making from some high pitched chirps and clicks when he was happy, and ear-shattering screeches when he was hungry or distressed, Harry also used words that he'd obviously copied from Lily and that godawful husband of hers. Vernon, upon learning that the new pet could speak, took great joy in teaching it to talk, growing amazed at how quickly it absorbed the language as well as the French he'd been picking up in anticipation of a business deal.
If there was one magical thing that Vernon Dursley didn't mind having around the house, it was Harry the Lizard. Not only was it reasonably well behaved, it also didn't do anything unnatural besides look human.
Petunia, upon discovering that Harry was semi-aquatic during a bathtime scare that nearly took a couple years off her life, got a kiddie pool for Harry the summer he turned two and placed it in the back garden so he could go swimming on sunny days. She didn't particularly like having a reptile in the house, especially since she was the one stuck cleaning the cage more often than not, but Harry seemed to make Vernon happy and Dudley seemed to be endlessly fascinated by him. Since having a pet was supposed to help teach a child responsibility...
When Harry was three, he swiftly learned why he couldn't have sweets like Dudley when he got into the cupboard where Petunia kept her special treats for her son, gorged, got sick, and had to be brought to his vet who had carefully observed him for a couple days to make sure he didn't die. After that, he was far less inclined to beg Dudley for treats, associating the cloyingly sweet taste of processed sugar with this incident.
When Dudley was four, he was rather firmly taught why cruelty to animals was not a good thing after he'd hit Harry who'd been promptly taken to the vet "just in case".
Things continued until they nearly fell apart when Harry was six. Someone had apparently gone and alerted the authorities to the fact that there was supposedly a second child in the Dursley home, and they came looking. When the social worker had caught sight of the growing boy in the growing reptile enclosure who'd been eating crickets, there had been words. Children's Services was happy when Harry was packed into Dudley's second bedroom for a time, but Harry who had rather liked his cozy enclosure with its nice warm heat lamp and the greenery that Vernon occasionally changed around so he didn't get too bored and his food and water available whenever he wanted it was not.
Dudley had been quite happy when his pet had joined him at school as part of the agreement that had allowed the Dursleys to keep Harry, especially since nobody else was allowed to bring theirs. Within a few days, Harry had grown bored with the lessons on reading, writing, arithmetic, and basic science and had started to wander off during classtime. Since Harry was a reptile and snakes and lizards didn't understand human things like school, the Dursleys said nothing about this when the school called yet again to inform them that Harry had been found playing on the swings when he should be in class.
When Harry was seven, a man in a suit, long coat, and tennis shoes who called himself "The Doctor" came. When Petunia got a good look at his eyes, teeth and nails, she was able to tell the man wasn't exactly a man and therefore let him in, since she had a good idea why he was there. The "man" who'd given the Dursleys a very dark look had taken Harry for two days before returning with a slightly older looking Harry. He looked very pale and rather sad as he returned him.
"Everyone seemed to think he was mine." said the man who gave the Dursleys some extra care and feeding instructions as well as informed them that Harry would more than likely outlive Dudley's hundred times great grandchildren if there weren't any accidents. This meant Harry wouldn't be dying any day now as the Dursleys had begun to fear might happen considering the short lifespans of some reptiles and had been trying to brace themselves for.
"Isn't people thinking he's yours a good thing?" Vernon asked the "man" in the brown suit who had hair nearly as messy as Harry's as he read over the information he'd been given, noting that it was safe to feed Harry cooked meat, which meant that he would be able to give in when Harry came to the table and started begging for scraps.
"...No." the reptile in the suit said sadly as a memory seemed to catch hold of him and set him to shaking. "They kept going after him to get to me."
Things started to go back to normal after that, aside from the fact that Harry got the occasional table scrap or bit of leftovers to supplement his usual meal of fruits, vegetables, and crickets, and the fact that Harry could often be seen playing with a holographic device that showed a man in a frill-necked robe who made similar noises to the ones that Harry used to make as a baby. Every summer, Harry would be allowed to lounge in the kiddie pool in the back garden soaking up every bit of natural sunlight he could get, and every autumn, Harry would return to school where he'd be interested in the lessons for about a day or two before he got bored and wandered off again prompting a series of calls from the school that would extend to the next summer. If Harry didn't get much for Christmas aside from a healthy serving of roast goose, that was okay. Reptiles didn't really do Christmas.
When Harry was eleven, a certain letter failed to arrive and put the house in an uproar. This was because - while Time Lords were very psychic - being telepathic, and able to sense the movement of the universe around them and the passing of time, they weren't magic. Dudley, who was very happy because he would be bringing Harry along to Smeltings with him, never knew what was missing. Petunia and Vernon however were relieved until the day they came.
Just because the letter didn't arrive didn't mean that the wizards wouldn't. Apparently, that Dumbledore fellow who'd dropped Lily's pet off on their doorstep had invested too much in that whole "Boy-Who-Lived" thing, and he needed a "Boy-Who-Lived" to show for it. None of the Dursleys were too happy about this, especially since their pet could get hurt if he got caught up in whatever the old man was scheming.
Dumbledore got an earful, but after several threats, the Dursleys were forced to relent if only to keep themselves and their child safe from the so-called Leader of the "Light". The Dursleys told Harry to come home for Christmas. Just because he wasn't people, and the word Alien was lurking around the edges unsaid, didn't mean he wasn't theirs.
And so, Harry left for a time. Petunia, who'd grown used to tending to Harry, found herself at loose ends when she looked over at the enclosure which took up half the living-room and the space where the cupboard under the stairs had been which they'd snuck Harry back into when Children's Services wasn't watching and found it empty with the heating light off. Vernon also looked kind of sad every time he came home from work and called out Harry's name, having forgotten he was gone until the small figure failed to appear to greet him. Dudley, who had been quite looking forward to bringing the family pet to school if only to watch as the teachers were steadily driven up the wall by him, had been rather livid and had naturally blamed the wizards who'd barged into their home and taken him.
Harry, who was being given "special lessons" at Hogwarts to cover up the fact that he was "Squib", didn't understand why the hell people were going on about the fact that he looked like his former owners who'd died and left him to the Dursleys, nice though they and their friends had been. He didn't understand why people kept going on about "abuse" when the Dursleys had treated him rather well considering the limited knowledge and resources they'd had on hand either. The Doctor had been a bit upset that he'd been kept as a pet, but better a pet than being used as a hostage every other day, as the Doctor had said when he'd returned him after that incident that had nearly resulted in both their deaths. Humans tend to take better care of animals than they do other people.
Wizards however...Considering what he'd heard some of them say about non-humans, and the research he'd done in the Library as he blitzed through the stacks, he was glad that it had been Lily and James Potter who'd found him and tried to take care of him until they'd died.
When the Holidays came, he signed up to go home and his Head of House who'd apparently hated both James and Petunia and therefore hated him because he belonged to them let him. Vernon, Petunia, and Dudley were waiting for him at King's Cross when he'd arrived despite the cold and the somewhat late hour.
The Deputy Headmistress turned up the next day to drag him back to school, and got bit for her troubles.
"That's not how you handle a lizard." Vernon said, chuckling at the woman's stupidity which had resulted in a bloody hand.
The woman left, vowing to return with reinforcements. Return she did the next day with a sad looking man and Harry's Head of House who stood glaring daggers at each-other behind her back. The sad looking man that Harry vaguely recognized as being Moony had pleaded with Harry to come back to school where he'd be safe and well cared for. Harry commented that he was quite happy where he was, and only his Head of House seemed to listen to him, seeing as he decided to go through with the rigamarole of capturing Harry and bringing him back to the school against his will because he was happy.
Finding out that Harry wasn't actually Lily's or James' offspring after he'd already ruined his Christmas, Harry's Head of House was apologetic and, as it turned out, suicidal. Fortunately, Dumbledore and Madam Pomfrey had managed to keep the man alive long enough to get him to St. Mungo's. After the unfortunate Professor returned to the school three months later, he became apathetic about everything, most of all his students who briefly enjoyed it until they realized that he wasn't going to grade essays or anything else for that matter, stop people from sabotaging their work, or correct their mistakes before they turned deadly. Fatalities in the higher-level Potions classes soon skyrocketed.
That summer, Dumbledore sighed as he allowed Harry to go home to the Dursleys knowing that, despite the fact that they thought of him as a pet, it was the safest place for him. Especially since the boy didn't have a lick of magic. Harry had naturally been happy to see the Dursleys waiting for him at King's Cross once more, and the Dursleys were happy when Harry was back home where he belonged. Petunia had even gotten him some mangoes despite the fact that they made a mess and Harry had to be cleaned up afterward.
As for Voldemort, he was doing what he'd been doing for about eleven years at that point, wandering around Albania wishing that the world would stop spinning and that time would stop passing so he could think. Considering the fact that Time Lords could live for millennia, he would be doing that for a long time to come.
Edited 7-19-15.