No, really, I do. Strange hair colors, odd piercings, things that can only be described as "unique". It keeps happening, and I'm not sure why. And almost to the last one, the freaks are always my favorite characters.
I came to this realization a while ago when considering the appearance of a particular character (whom I LOVE). I can see her clearly, owing partially to the fact that she was one of my rare "came to me in a dream" characters. This particular social outcast has hair that looks like it should be a flag for some obscure nation no one's ever heard of. (You know the ones I mean - the smaller the country, the more ornate their flag).
Elodie (who dropped the "M" because she wasn't "feeling it") has crocheted hair. It's sage green on the bottom, followed by a layer of black, a layer of red, and the bulk of it is cream colored. Straight across the top there's a streak of lime, scarlet, and violet.
I can see her as plain as day, and the appearance really does fit her character. She's destiny, and well, destiny has her own ways about her.
This wasn't an intentional writing quirk, but I've seen it crop up again and again in different WIP. One MC has dyed her hair cherry red (for a plot reason: she's in hiding and the dye makes sure people don't notice her face). In another, hair dye is a supernatural deterrent because the smell puts off the beasties that would like to make the people snack foods. And in another, the MC's hair is pink because she's trying to make herself look like an anime character. (don't ask...)
That's not to say it's always dye - one character has almost clear hair which is a result of something akin to albinism - but still, it's a weird and, well freakish common thread.
The usual mode of "I'm teh speshul" in books is those dreaded purple eyes, but I scrapped that one a long time ago. One charrie does have red eyes, but again, that's biology not anything mystical and speshul making ;-)
I'll also say that the appearance is one component of the characterization. They all have personalities. Pinkie's brash, as is Miss Destiny, but others are painfully shy or awkward, and so far no one who's read excerpts seems to think that the odd appearance thing is a big deal. (Most of them LOVE Pinky - no, that's not her name. Heck, I love Pinky. She's the biggest unintentional troublemaker in the world.) But put up, side-by-side, it's disturbing.
Anyone else have a quirk they didn't realize they had? Do you go with it or give into the urge to alter your WIP?