I'm all for monsters that don't have a strictly mythic or folkloric origin, some of D&D's originals have themselves crossed into popular consciousness too. But recently I found myself unable to ID the origin of a particular creature: the Raggomoffyn. As a monstrous sentient pile of laundry that yearns to control your body and glam out. The word "ragamuffin" is apt, at least (unlike, for example, the Lamia which has been represented more ways than I can be bothered to figure out.). But the only othe uses I've found had been a breed of cat and a Carribean space opera. Anybody willin to take a stab at where this creature originated?
A raggamuffin is also a term for a dirty, lost, or shabbily dressed child, such as an orphan or street urchin. The word has been used to refer to a number of rather scary little creatures in some circles, usually to invoke the same sort of imagery that disturbs the audience. Often used as a sort of childlike undead, or an evil spirit, or as you mention some possessed rags. It varies, but the origin is that of a shabbily dressed child. I'm not sure that there is an old folklore for it as a monster or not, and I think it may be a more modern convention.
Who knows though? Someone might surprise us with more insight.
To get an idea as to the type of strange imagery that the word invokes when speaking of a monster, this magic the gathering card "Ragamuffyn" has the kind of almost cutesy yet creepy imagery that is commonly associated with the term. Childlike, yet seemingly unnatural. I've no clue as to why D&D specifically made the things about possessed clothes or somesuch, unless they were going by the shabbily dressed aspect and less so about the urchin child aspect of the word.
...a sort of childlike undead...
Why did I immediately think of the Attic Whisperer?
But Raggomoffyn is also a evil spirit born from the death of a young homeless orphan. Usually they act as a Poltergeist and torment people who mistreated them in life. Their favored method is possessing clothes and attacking.