(minor clarification to Author Notes added, 6th December, 2016)
Disclaimer: I am not J.K. Rowling. I do not own Harry Potter.
Note: The following scene takes place by the Hogwarts lake on the summer afternoon of 1976 just after Defence OWL exam and is set in an alternate universe where Severus Snape had a somewhat different background from canon. As the scene opens, James Potter is complaining to his friends, Peter Pettigrew, Remus Lupin and Sirius Black (although Remus doesn't say or do much in this piece, but he's still technically there) on a theme with which they are somewhat familiar. This piece is a one-shot.
Rating: This piece is rated 'T'.
"What," James Potter glared at where a particular dark-haired Slytherin was surrounded by a gaggle of admiring young women, most notably, one Lily Evans amongst them, "has that penniless, flea-bitten, barely literate, excuse of a wizard got that we haven't?"
It was the summer of 1976, and on a warm sunny afternoon, James Potter and his friends had been doing their best to unwind after a particularly tricky Defence theory exam, by Hogwarts' lake. They had to some extent been succeeding, until one Severus Snape and his horde of 'admirers' had happened by, to vex them – not that Severus Snape was currently overtly doing anything other than existing, to vex James Potter, but not that he either actually needed to do anything other than exist in James' mere proximity in a fashion such as this.
One of the witches in attendance upon 'Snape' was giggling as he laid a hand on one of her arms and inclined his head to whisper something in her ear.
"He hangs out with Hagrid, the school groundskeeper." James Potter continued his (to his friends, by now familiar) diatribe. "He's a social embarrassment, or at least he ought to be."
"It's the gypsy thing." Sirius Black sighed, raising this point, as he frequently did. "It makes him romantic. It makes him dashing. It gives him 'sex appeal'."
"It makes him bloody penniless, and a nobody from nowhere – a wandering vagrant, with a thief of a father, and a mother who ran away from respectable society to frolic with him – and it should give him no appeal at all, whatsoever." James huffed in exasperation.
James Potter had taken against the tall, lean-and-tanned, gypsy half-blood on the first Hogwarts Express ride, almost five years ago, and had had his dislike further enhanced, when 'Snape' had been sorted into Slytherin, the house where every witch or wizard it contained was – it was a fact known to all good Gryffindors – irredeemably vile. Mind you, even James couldn't say that Snape was in any way bigoted, prejudiced, or as unpleasant in certain fashions as some of his fellow Slytherins. He was Slytherin in a thoroughly sly fashion though, with things occasionally going missing where he might have been, and unexpected jinxes and hexes appearing on items or turning up in places to inconvenience those who counted themselves his enemies. And he was highly sneaky – at least as good as going unobserved about the place as James and company, and they had the advantage of James' ancestral invisibility cloak to help them out.
All in all, Snape had been thoroughly vexing through most James' Hogwarts career to date, and that had been before the boys and girls in their year had gotten to the ages where they had started to 'notice' one another in a 'more romantic' sort of sense, and Snape had within weeks become a magnet for female society. At that point Snape's ability to infuriate James at mere sight had attained stratospheric levels.
James pouted as he practically always did, when Sirius pointed out the (from James' point of view) 'down' side of the 'gypsy thing'. Unfortunately, literature and music was full of romantic, dashing, attractive gypsy figures and Snape, with his (dis?)honest-to-goodness muggle gypsy of a father, was practically as gypsy as they come. Apparently he and his parents toured muggle Britain in a gypsy caravan, pulled by bloody-great-horses, tweaking the noses of the muggle police authorities in a dashing, romantic, way. James wished that the muggle police were more efficient and had found some excuse to lock the whole damn Snape family away, years ago. It hadn't been so bad in James' early Hogwarts years, but that had been before Lily Evans had started to become quite so pretty a witch; only she was in spite of her prettiness – as was practically every other female without a grain of sense in their head – to be frequently found in the company of Severus Snape. Had in fact been in his company for a touch longer than many, having apparently encountered the family Snape whilst they were camping wherever it was that she lived.
Life just wasn't fair…
"Cheer up Prongs." Peter said, as he sometimes said. "Gypsy dramas end badly, at least some of the time."
"That's no good if she goes down with him." James grumbled, as he frequently did. "Lily. My Lily."
In this universe Tobias Snape is assumed to have been a (muggle) 'gypsy' of indeterminate (although roguish and living in a horse-drawn caravan) variety, whom Eileen Prince ran away from her family to marry. As in canon, they only have one child, Severus. Severus did not see much of Lily (or Petunia) during his childhood, since the Snapes tended to move around the country, although Severus did encounter the Evans sisters a time or two when the Snapes happened to be camping near Cokeworth. Severus Snape was barely literate at the age of eleven and required some persuasion to attend Hogwarts - in the end, it was the presence at Hogwarts of Rubeus Hagrid (who likes animals and 'natural' stuff) which swayed him on the issue.
This version of Severus has been sorted into Slytherin, but is uninterested in most dark magic or wizarding bigotry or politics. His primary 'academic' interest is potions brewing, although he has a (mostly extra-curricula) interest in magic that involves sneaking around or which can be left as a nasty surprise on an object or in a place for taking revenge on enemies. He has no interest at all in dueling.
I regret to note that this Severus is not above pilfering items, although at Hogwarts he never removes other people's things for his own use - he purely removes objects belonging to enemies to hide them somewhere or to plant them on someone else, for 'spite'.
This Severus 'hangs out' with Hagrid to discuss animal care, or to engage in woodcarving (in which they are both interested). Severus remains not very interested in books, unless they are about potions or animals (directly, or on matters pertaining to them). He is highly numerate however – at least when it comes to anything to do with money matters.
James Potter is unlikely to win Lily Evans' hand in this universe if Severus maintains any interest in her. James just can't compete with the whole 'dashing romantic gypsy bad boy' appeal thing.
This Severus is unlikely to join the Death Eaters, post-Hogwarts. Sure, he'll work for them, if they pay him cold, hard, cash, up-front, but then he'll work for Albus Dumbledore, on the same terms, and Albus Dumbledore is in a better position to 'get in first' in snapping up Severus' services – Albus might not have liked or trusted this Severus otherwise, but Albus will have had Rubeus Hagrid singing the praises of 'that Snape boy' to him for seven years by the summer of 1978.
And threatening anyone whom this Severus considers his close family (such as his parents, current girlfriends/future wives, maybe his head of house (Professor Slughorn admires him for and gets on well with him on account of his potion-brewing), and Rubeus Hagrid) is a very bad idea, unless the objective is to make him an implacable enemy.
This piece is a one-shot.
Clarification: (6th December, 2016)
When Severus is 'at home' the Snapes tend to usually travel as part of an isolated family unit - consisting of Tobias, Eileen, Severus, the horses, and the pet cat(s). They occasionally meet up with other gypsies, though, for occasions such as the Appleby Horse Fair.