Ah, yes, magical cloaks. The first line of defense for adventurers. I think every one wants one, especially the Elven variety. Question: why does the thief always get the one the party finds? I mean, hiding in shadows and moving silently is a class ability for the thief; he shouldn't ~need~ a magic item to do it for him. And why do the elves in the party just let a ne'er-do-well thief take an item of such cultural significance? Take The Lord of the Rings, for instance. It's made quite clear that the cloaks that Galadriel gives out to the party are special. She says that never have they clothed strangers in the clothes of their kinsmen. Or something along those lines. Regardless, I think that elves might have a thing or two to say about some sweaty lowborn human gallivanting around in one of their kinsman's cloaks. Or maybe that's just me; I tend to be a prick and play both PC and NPC elves as snobs. Well-intentioned ones, to be sure, but still snobs nonetheless. Hey, if you lived anywhere from several centuries to, well, forever (depending on the world/source), I think you'd act a bit high and mighty as well. And don't forget the fact that anything a human can do, elves can do better. :)
Of course, there's more to it than just the Cloak of the Elvenkind. What about the Cloak of the Bat? After the release of the 1989 Batman with Michale Keaton, my character at the time managed to acquire one. Cut to the game and, well, I guess it was inevitable that my character grab a bad guy in a bar and say, "I'm Batman!" before head-butting the poor fellow.
What about a Cloak of Protection for the magic user? And robes, while not cloaks, sort of fall into this whole area as well. Robe of Useful Items: sometimes comical, occasionally helpful. Robe of Stars: I can breathe! Etc, etc.
Remember, clothes can make the man! Or eat him.
AC: 3 /1  Special: Wrap attack
HD: 6 Move: 1/15 (when swimming)
Attacks: Tail HDE/XP: 8/800
Cloakers are a strange subterranean race that inhabits the dark places of the Underdark. They are thin and leathery with glowing red eyes and a mouth filled with razor-sharp teeth. Its back is covered in eyespots (thus negating any possibility of surprise) and it has a small club-like tail with which it can attack twice in a combat round. Cloakers are highly intelligent, but their thought processes are so alien that it is nigh impossible to communicate with them. In fact, some sages speculate that the cloakers came to this world from the Outer Dark.
Its favored means of attack is to fly at its prey and envelop it like a cloak (hence their name). Once a victim is enveloped, it uses its tail to fend off any would-be rescuers and bites the enveloped creature for 1D4 + victim's AC points of damage (1D4 + [19 - victim's AC] if using the ascending AC system). If the cloaker is attacked while feeding, damage is split evenly between the cloaker and its victim; area effect spells do full damage to both. Note that the creature's tail can be attacked; it is AC 1  and can take 16 points of damage.