Changeling!Tim’s childhood is... actually kinda horrifying, when anyone looks into it.

(CW for forced medical procedures, and abuse in the form of temporary imprisonment. Also, minor self-harm, and… I don’t know what you call “eating something that will make you sick so your parents don’t get mad at you,” but I know it ain’t good.)

Tim had pretty pronounced fangs when he was younger, which his parents were just planning to wait out... until he was fast coming up on 10 and it was clear Tim wasn’t going to lose his teeth. A quick x-ray proved that Tim didn’t have adult teeth to grow in, just the one set he came with, and the fangs were only getting more obvious. His parents found an orthodontist willing to yank the fangs & wire up the rest of Tim’s teeth with braces to force them to look smooth & even as he grew up. (The doctor kept the teeth as a curiosity, and a decade later Damian will track that doctor down to steal them back.)

Something even Tim didn’t realize until he had to undergo a full Justice League-grade medical exam in preparation for becoming Robin, is that the tiny points on his ears aren’t natural. They have no idea what the ears of the baby Jack & Janet received looked like, but Tim’s points are actually mostly scar tissue. (Bruce puts it down as “a cosmetic procedure not dissimilar to ear cropping in canines” and tries not to feel sick.)

(There was also a period where the Drakes did an awful lot of research into cosmetic eye surgeries, but they eventually gave up. Apparently, it was a bigger concern that their son might end up blinded than that his eyes glowed in the dark and/or were the wrong color.)

As I mentioned before, Tim’s parents trim his thorns so that nobody goes to ruffle Tim’s hair and realizes he’s not human. He... actually started doing it himself when he decided to become Robin, because Tim has seen Bruce ruffle Jason & Dick’s hair so many times and didn’t want to hurt Bruce (or experience the absolute agony of having a thorn get caught in Bruce’s gloves and end up ripped out of Tim’s scalp,) as well as not wanting to give away Tim’s own inhuman nature with the single most obvious trait he has. (When the rest of the family find out, they are horrified and insist that Tim stop doing that. Instead of hair-ruffles, Tim gets hair-strokes that go only in one direction, bumping harmlessly over the curved outer edges of his thorns; it’s actually very soothing for both parties. Everyone absolutely uses Tim’s thorns as a stim toy, as long as Tim’s okay with it.)

Tim’s parents also hire an in-house barber to cut Tim’s hair, so they can make sure it’s “properly disposed of.” (Tim’s nightmares always smell faintly of burning hair.)

Tim wears fancy dress gloves to all dinners, because with the uppercrust you never know if someone’s going to bring out the real silverware. (If someone tells him to take off the gloves or Tim’s skin happens to brush up against somebody’s jewelry, Tim just sorta has to... deal. It’s rude to rush out or refuse your hosts, after all.) (Fortunately, Dick and the Titans all prefer reusable plastic silverware. And as soon as any Bat finds out about Tim’s fae nature, Wayne Manor quickly switches to stainless steel.)

It’s nearly impossible to know if a meal was prepared with iodized salt or non-iodized salt until it’s already in Tim’s mouth and the burning-itching discomfort of coming in contact with an anti-fae substance begins. It’s rude not to at least try the food someone offers you, and it’s even ruder to just spit something out, especially out in public. At least Tim doesn’t usually have to fake it when he says he’s not feeling well in order to stop eating. (Tim doesn’t tell the Waynes about this until that medical exam, where he kinda jokes about being allergic to salt and someone’s like, “Wait, how do you eat? Everything has salt in it nowadays.” Alfred rather forlornly puts his sea salt up on the top shelf and buys a jar of iodized table salt on the next grocery run.)

Tim’s blood is immediately identifiable because it has chloroplasts in it. No, he’s not actually a plant; yes, he can perform limited photosynthesis. No, Tim was not aware of this about himself, he’s never been allowed to give blood before, and like??? Sure, he figured out he was a changeling, but that does not immediately translate to, “Oh, I should test my blood for plant cells!”

Tim’s room doesn’t look any different from any other boy his age... except for three nails over the door on the outside. For the iron horseshoe Tim’s parents hang there sometimes, when they don’t want him to bother them or when he’s grounded. (Thankfully, it's been very rare for Tim to actually be trapped in his room, as setting up a salt line on his windowsills has always been... well, he's not sure. A step too far, even for his parents? A step too many to remember and/or perform in the heat of the moment? Something they don’t even realize is necessary, assuming the horseshoe prevents Tim from leaving the room at all rather than simply crossing that one threshold? Tim doesn’t like to think about it. Tim typically stays in his room anyway when he feels the swooping nausea of it hanging over his door, if only so his parents don’t find him missing and decide sealing the windows is something they ought to be doing. Trapped not by any law or binding ritual, but by Tim’s own admittedly rare fear of consequences.) (After Tim is snatched by faerie hunters, Jason and Dick are the ones who search Tim’s house. There’s a moment of silence when they find the horseshoe and realize what the nails are for. “I really hope I don’t have to point this out,” Jason says, in the tone of someone who’s going to do it anyway, “but it’s never a good sign when a kid’s bedroom has a lock on the outside.”)