Doghead Thirteen

Calum Wallace, AKA "Doghead Thirteen", is the author of about a dozen Fanfics, including several delightfully deranged Harry Potter stories and a complex set of interlinking Mega Crossovers. Among other things, he is known for the very... different versions of Harry Potter who show up in his works.

His major projects are:

Enter the Dragon, a Harry Potter fanfic which would have eventually crossed over with Shadowrun. In it, Harry is turned into, well, a dragon by a freak magical accident at Stonehenge when he is eight. Unable to support his literally all-encompassing appetite (Dragon!Harry eats meat, every plant that grows, random potions ingredients, coal, pig iron and sheet steel, and drinks both water and petroleum products of all kinds), the Dursleys call upon Dumbledore, who moves Harry to the grounds of Hogwarts. There he is raised (and studied) by the school staff, whom he comes to view as his family (yes, even Snape). As he grows, he has interesting conversations with those who are aware of his presence there, decides what constitutes being a "proper" dragon, and sets about to live his life accordingly. The story is currently abandoned at the point where Harry and Hermione are about to board the Hogwarts Express for the first time (although there is also a file of notes and bits taking the plot all the way past Halloween 1981 available to the dedicated reader). Wallace has indicated that the core Gimmick of the story is hyperactive!dragon!Harry, and in the long term he would either have to move away from this characterization as Harry matures, losing what is arguably the story's main appeal, or leave Harry hyperactive and immature even as his classmates become adults. Unable to resolve the dilemma, Wallace suspended work on the story and offered it to anyone who cared to try to complete it. At least one author has begun an attempt.
The Book of Dobby Reboot: Per Arcana ad Astra, which is an AU diverging at the end of Harry's fourth year, eventually crossing over with Girl Genius. Kicked out of Hogwarts for political reasons, Harry intends to take the fight to Voldemort in a way that neither the Dark Lord nor the Ministry is equipped to understand. Dobby is organizing the house-elves into as close a replica as possible of the RAF circa 1940, the Gringotts goblins are apparently the Jaegers -- and Hermione is a Spark. It's crack, but highly entertaining; also incomplete. It's a reboot/Retool of an earlier incomplete story, The Book of Dobby: Per Arcana ad Astra, which is different enough to be worth checking out as well. This, too, has been abandoned, for less clear reasons than Enter the Dragon.
Top Dog, a really huge Mega Crossover universe patterned in form after Undocumented Features. The main continuities are Enter the Fnords, which is Harry Potter with a severely traumatized and Badass Anti-Hero Harry in a magical world upgraded to fit into Top Dog's intergalactic politics; Biker Half, which is Ranma ½ with Ranma the heir unaware of one of the strongest Amerai clans; and A Fox in Tokyo, which is Naruto with guns and Claymore mines, in a Konohagakure transplanted into the Nerima of Biker Half. Epic storyline, and a wonderful series of funny moments as you see the canon universes fitting into the crossover. As of the end of 2019, Top Dog is officially on hiatus.
The Sea King, a crossover between Harry Potter and Deadliest Catch. This is a short story, unlike most of his other work, and complete.
His current active project, not yet entirely available to the public, is The Scourge From the North, a cross between Harry Potter and an idea from Warhammer that's been lifted out of its original context and mutated dramatically, along with a bit of Girl Genius (again) -- and, most recently, The Elder Scrolls V: Skyrim. Living in and around the Orkney Islands (and parts of Scandinavia) are the Orcs, a subgroup of magical humanity who are very large Viking-like folks, mostly not wand-users, who are very good at violence and have no aversion to using any Muggle technology that suits their needs (like machine guns and armored trucks). And Harry Potter, who has recently been affianced to Pansy Parkinson as well as taken Hermione Granger as a concubine, is their uncrowned king. They learn about him at the beginning of his fourth year, and vow that he will not be kept from his people and assassinated as his father -- another uncrowned king -- was. By the time the Goblet of Fire spits out its (not entirely expected) choices, an army of Orcs several thousand strong is on its way to Hogwarts to protect their king. Meanwhile, a fortified bunker is already being built in the Forbidden Forest by their advance scouts as they go to war with those centaurs who haven't decided to make a run for France. Features an increasingly tech-savvy Harry who's turning the Chamber of Secrets into a high-tech supervillain lair with the help of a few house-elves, a different course for the Tri-Wizard Tournament, a civil war cleverly fomented among the Death Eaters, the return of Lily Evans, and both Pansy and Hermione in bondage. Among many other things. Definitely NSFW, as of the end of 2019 it consists of eight very large, complete chapters that are only available through a specific mailing list, and is as yet incomplete.

Doghead Thirteen provides examples of the following tropes:

Alternate Universe Fic: Most of his fics, especially his large projects, are based in AUs of some variety. Top Dog is built by welding multiple AUs together into a single continuity.
Big Brother Is Watching: One minor subplot in The Scourge From the North follows the centaurs who decided to make a run for France -- and how they appear to be destroying the Statute of Secrecy in the process by being completely unaware of surveillance cameras in places like, oh, the Channel Tunnel.
Bodyguard Babes: Subverted by Babette in The Scourge From the North, who appears on first glance to be a child. But only on first glance.
Brains and Bondage: As seen in his depictions of Hermione.
Casual Kink: Light BDSM (playful spanking, mostly) shows up occasionally, usually between Harry Potter and Hermione Granger. The Scourge From the North goes well beyond "light" without getting particularly Squicky.
Children Are Innocent: Definitely in play in some scenes from chapter 7 of The Scourge From The North, wherein a pair of human children and a centaur girl who meet in Europe become fast friends, with neither side more than slightly curious about their physical differences from each other.
Creator Thumbprint: In his Harry Potter fics, you will frequently see House-elves speaking hilariously over-mangled English (and who don't think anything like a human), Harry-Hermione shipping (sometimes with a touch of playful BDSM), and a Harry (or Hermione) who is mechanically inclined at a level anywhere from handyman-tinkerer to self-taught aerospace engineer. (Or genuine Spark.)
Blue and Orange Morality: House-elves in general in Doghead's fics -- and especially in The Scourge From the North -- are about ten degrees off center compared to humans when it comes to their mental processes, starting with their canon willingness to be unpaid servants and going from there.

Dobby blinked a couple of times, very visibly startled, then said “Ooooh! Youse is holdses on,” selected a large adjustable wrench, and vanished with a pop; a few moments later he was back, brandishing the wrench and saying, “Yes, Dobby is has helped the noxious Mr Filch go to sleeps, now wees is goes and checkses out the Come-And-Go-Room!”

Gun Nut: A major element of Goblin culture in Enter the Dragon, although in a more rational/military form than the usual "gun nut" in fiction. They manage to transmit a fair amount of their attitude toward guns to Harry.
Hands Off My Fluffy: Simultaneously invoked and inverted to amusing effect in Enter the Dragon. Hyperactive!Dragon!Harry -- who's about 8 or so -- knows that dragons in stories get treasure and maidens. Too innocent to know better, he decides maidens are another, better form of treasure, and when one is finally offered to him -- Suze, daughter of Bane, from the centaurs of the Forbidden Forest -- he treats her very well indeed. And once she realizes that she's dealing with a child and not a ravening monster, she comes to adore him as a kind of little brother, and she slaps her father when he tries to attack Harry not long afterward.
Hidden in Plain Sight: Harry, in The Sea King. He changed his name and moved to Alaska; that was it for hiding. The bridge and his quarters on his ship are practically wallpapered with all his wizarding belongings, he has a reputation for miracles at sea, he allowed himself to appear (at least as a voice) on Deadliest Catch, and he named his ship Hermione.
The Madness Place: A major plot element in The Scourge From the North, initially as proof that Harry is worthy of being the King of the Orcadians, but also playing a major role in subsequent plot developments.
Magitek: Shows up in his works. Book of Dobby heads toward blending WWII technology with magic. And Harry, some of the Orcs and even Lilly Potter come up with some surprising innovations in The Scourge From the North.
Muggles Do It Better: The core idea behind Harry's plan in The Book of Dobby.
Mythology Gag: Doghead frequently locates Hogwarts about a dozen miles inland from the coastal Scottish town of Mallaig. The railway near Mallaig was used by the Harry Potter movies for a decade as the shooting location for the Hogwarts Express.
Nietzsche Wannabe: In Doghead's fics, Snape is frequently portrayed as viewing Wizarding Britain as a "sick joke of a world" and either in favor of or actively working toward its total destruction and sometimes its replacement with something -- anything -- else. He's usually right -- and in The Scourge From the North, Harry eventually agrees with him as he learns more and more about its underpinnings.
Parental Abandonment: In Scourge from the North, Hermione has been raised by her aunt and uncle, who rescued her and took her in when her actual parents decided caring for a baby cut too much into their social life and left her to die in their garage.
Pluralses: One of the distinguishing features of house-elf dialog in Doghead's Harry Potter fics.
Remote Body: Hermione figures out how to do this with golem limbs and full golem copies of herself in The Scourge From the North.
Shipping: Is very much a Harry-Hermione shipper in the Potter fandom.
Shrouded in Myth: Minerva McGonagall in The Scourge From the North -- she's been visiting the Scottish town of Mallaig for her favorite treat almost weekly for decades, and doesn't realize that its Muggle population has noticed, and has produced several generations' worth of legend and speculation about her.
Tuckerization: Among Harry's friends and neighbors in the Alaskan town where he's lived for years in The Sea King are Emma Watson (a mother of two) and Danny Radcliff (a forklift driver). Googling other characters' names will reveal more examples.