Height: No clue. At the moment I'm guessing somewhere near six feet, but someone much more familiar with the height of Naruto characters in relation to eachother could answer this better than I can.
Medical Info: Seemingly incapable of dying or staying seriously injured for long. If he suffers any sort of wound that doesn't involve the body part being separated from the body, it will heal itself. However, if he DOES lose a body part it seemingly has to be reattached before it can heal up.
Eyes: Kind of hard to tell at the moment.
Hair: Silver-ish/gray, apparently. This is unfortunate because clearly he should be blonde.
Physical traits: Most notable thing about his look is his robe and the huge scythe he carries around. If you are talking to him, there is about a 95% chance that he's carrying his scythe around. Hell, it's tied to his wrist.
What's Okay To Mention Around Him/Her: Pretty much anything. However, Hidan is taken from canon prior to the fight with Asuma and as such, he doesn't know about it. And if he did know about it he would kind of be a total dick and press trauma buttons for fun. So if for some reason you know about that, which is admittedly fairly improbable, don't fill him in.
Abilities: Aside from the whole "can't be killed" thing? Well. Hidan claims to be the slowest member of Akatsuki, but that's kind of like being the worst basketball player in the Harlem Globetrotters; he's not as good as the others but he can still fuck your shit up. His primary weapon is his three-bladed scythe, as seen in the icon over there; it's tied to a rope that goes around his wrist so that he can throw it around as he so pleases. Additionally, the blades themselves can apparently separate themselves a bit to get even more range. The scythe isn't designed for sheer efficiency and destructive power in terms of fighting a single opponent, but rather it's designed so the odds of it connecting even slightly and drawing blood are high.
Now, once Hidan's managed to draw blood, then the fun begins. First, he'll draw (or already has drawn) a triangle surrounded by a circle on the ground using his own blood. One he's got the opponent's blood, he ingests it and steps within the circle and takes on an appearance that's somewhere between Grim Reaper and voodoo priest. As long as he remains within said circle, any damage inflicted upon him will be inflicted upon his opponent as well, with the major difference between them being that because of the whole "immortal" thing Hidan isn't going to die from any of the wounds he inflicts upon himself, usually with a pike. The opponent? Not so lucky. The only way to counter this is to get Hidan to step out of the circle, though if he steps back in afterwards it's right back to the torture thing. But this also seems to be his only significant power, so he's kind of a one-trick pony.
Notes for the Psychics: Completely cool with the whole killing other people thing and even greatly enjoys inflicting pain upon others. So yeah, if you enter his mind, it's not the nicest place around. His thought patterns when he's not in "and now I'm gonna kill everyone in sight" mode are relatively normal, though.
Can I shapeshift/bodyswap/spit at/step on/etc?: Probably, yeah. Just ask me in advance, of course, for anything like bodyswitching and camp effects and so on.
Maim/Murder/Death: Well, Hidan won't die. If there's a way to kill him, it hasn't been revealed in canon. But YES. Hidan is a psychopath and a dick and will probably get into fights on repeated occasions, and his entire thing is that he can get hurt and pop right back up. If you want to try and hurt him, do so, seriously.
Cooking: Ahahahaha yeah right.
Now! Here's where I get permission from you, o reader. Interactive fun! So, Hidan is a murderous bastard. His entire religion is based around killing and causing total chaos. And as such, that means that he isn't going to pull his punches in a fight or think much of snapping on someone. So, basically, it goes like this. If your character is a non-combatant, I'll make sure it never, ever comes to that unless you don't actually mind. Instead, Hidan will just be snarky and bitchy and do that retarde shounen villain thing where he's like "you're not even worth killing" or something.
If you are a combatant-type character and you're okay with Hidan trying to fuck your shit up, comment here and let me know. I'm going to try to avoid it much of the time because I'm not so good with the RP fighting, especially not with someone like Hidan who will keep coming at you until either you're dead or he can't fight anymore, but it would be OOC for him to not go for the throat when that pissed off, so yeah. Comment away, commenters.
Current Music: The Rolling Stones - Sympathy For The Devil