Hi! Thanks for writing for me. Feel free to have a look at some of the other exchange letters I've written. You'll find that my general preferences for those - plot and characterization, humor (light or dark), fleshing out minor characters or aspects of a setting that are only briefly touched on in canon - mostly hold true here as well.
In terms of shipping, I prefer gen or canon relationships (unless otherwise noted), and I will be perfectly content if the rating for anything focused on a pairing doesn't go above PG13. If you do decide to write sex, though, I would rather have an awkward but fun or character-developing encounter than mind-blowing multiple orgasms. No noncon, incest, bestiality, omegaverse, or unexpected bodily fluids, please.
For tricks, I generally prefer psychological horror to blood and gore, though I do have a certain fondness for end-of-the-world scenarios, with or without zombies. The one thing I really don't want is a situation where a POV character is broken down through extended torture, even if there's no explicit violence involved.
The prompts below may seem specific, but they genuinely are meant to be suggestions. If you're struck by a different inspiration, please feel free to follow it, as long as you avoid the do not wants. Working in Halloween or other seasonal themes somehow would make me very happy, but a sentence or two would be more than enough to accomplish that; it doesn't have to be a major focus unless you want it to be.
Thanks again, and I hope you have fun!
Batman: The Animated Series (any)
Treat: There's an issue of the comics where everyone makes sure Batman has a Christmas free of calls for help. Wouldn't it be nice if someone arranged something similar for Halloween, or simply because Bruce needs a break? (Or maybe Harley just manages to convince the Joker to take the night off.) Alternatively, a memory of young Bruce trick-or-treating or having some other bonding moment with his parents or Alfred.
Trick: Halloween in Gotham can't be a particularly pleasant time: it's hard enough fighting the usual costumed menaces when you don't have to worry about civilians dressing up like them. Somebody's bound to take advantage of that. Alternatively, something that plays on the Lovecraftian mythos and "Arkham Asylum." (I know there was an Elsewords that did this, but I've only read bits and pieces of it, so feel free to draw from it or ignore as you see fit.)
Additional canon-specific notes: If you want to pull in characters and concepts from other corners of the DC Animated Universe, by all means.
Harry Potter (Fabian Prewett, Gideon Prewett, Fred Weasley, George Weasley)
Treat: Okay, technically pranks are tricks, but emphasis on the "a good laugh is had by all, even the prankee" variety. Bonus points if carried out under circumstances where everyone really, really needs a good laugh.
Trick: For the Prewetts, the First War is probably horror enough. For the Weasleys...well, there's plenty of "war is hell" options there, too, but maybe George attempts to contact Fred from beyond the grave, with less-than-optimal results. Alternatively, the Inferi apocalypse happens (in either time period).
Additional canon-specific notes: I'm not a huge fan of Sirius (blasphemy, I know), so while I imagine he and the Prewetts got along swimmingly, I'd rather keep him in the background to give other characters a chance to shine if you're writing in the First War time period. Also not a huge fan of "Voldemort wins" scenarios, unless he's messed things up enough to trigger the apocalypse. And if the target of the twins' pranks is Percy, I wish to stress the "a good laugh is had by all" point; yes, he's a stick-in-the-mud, but that's part of his charm as far as I'm concerned.
Frozen (Elsa, Anna, Hans, Olaf)
Treat: So we know Olaf's excited for summer. How does he feel about autumn? Alternatively, Anna and Kristoff out on a date. Or sisterly bonding; I will never be able to get enough sisterly bonding.
Trick: Have you heard the creepy modulated version of "Do You Want to Build a Snowman?" that makes Anna sound like a vengeful ghost? A story/illustration built around that would be cool (no pun intended). Or maybe a "what if?" where Hans succeeds in his plot to marry one of the sisters before anyone catches on. And of course, there's always Evil!Elsa...though if you can figure out a way to pull off Evil!Anna, I'd love to see that as well.
Additional canon-specific notes: If you want to do a crossover with other Disney properties (Marvel included), feel free.
Gunnerkrigg Court (Surma, Antimony)
Treat: Anything that fills in some of the blanks in Surma's life, from her early school adventures with the gang, to how the heck she wound up marrying Anthony, to bonding moments with Antimony would be awesome. For Annie, any lighthearted adventure with Kat, or training with Parley, Smitty, and/or Jones, or just exploring the Court and/or the forest would make me happy.
Trick: A story about a psychopomp or medium experience that didn't go well would be interesting, particularly if the latter involves some tension with the Court, Coyote, and/or the robots. And I don't know what the deal is with Anthony, but I have trouble imagining it's good. (Though like I said above, please feel free to try and convince me otherwise.)
Additional canon-specific notes: Annie/Kat is an exception to my general "canon couples only" preference, though if you just see them as friends, that's perfectly fine as well. Other characters I wouldn't mind seeing make an appearance if you can find a way to work them in include Reynardine, Zimmy, and Gamma.