Who really knows how many Doppelgangers have appeared in the Legends of Windemere series? Not many because revealing several main characters have been copies of the originals for most of the adventure is stupid. I mean, could you imagine being invested in something for so long and then find that the characters you love are not really them? (Any comic fans know what ‘big event’ I’m poking fun at here?)
These creatures might be in the wild, but nobody really knows. There have been times when a hunter kills an animal only to see it transform. Doppelgangers have bluish green skin that is slick to the touch and no facial expressions. Yet it does have a mouth, which appears to bite a ‘victim’ and absorb their form and memories. It is never a perfect change due to the mental aspect. Many times a Doppelganger will take on the ‘idealized’ version of a person until they have a day to adjust. Not to mention they need to learn the person’s behavior to make it a believable copy. The change is done with the help of a colony of parasites that help them maintain and erase the forms. Fritz goes into a long description in Prodigy of Rainbow Tower.
The role of doppelgangers tend to be decoys for the wealthy and powerful. It is not a safe job and they are practically slaves. Some are used as bodyguards though because they are very strong in their natural form. Limbs can be stretch very far and reattach rather easily if severed. They some regenerative powers too. Many times a kidnapped decoy will revert to its normal form and kill the criminals, which makes these creatures assassins as well as spies.
One big part of the shape-changing ability is that they need to ‘taste’ the target and lose everything once they revert. Another ‘taste’ is needed to regain the form, which is why some doppelgangers are given a lock of hair, fingernail clipping, or something to regain the form if need be. This hasn’t always been the case. Every once in a while, a doppelganger will be born that doesn’t need the ‘taste’ or even physical contact. This is a prehistoric throwback since it can’t copy memories, but it has a superior transformation power. When people come across one of these types, they either hire it as an assassin or try to give it a psychic item to give it the memory stealing ability. This rarely works because doppelgangers have an aversion to magical items, which cause issues with their natural abilities.
As for out of story origin, the doppelgangers are a pre-existing creature. Not only in D&D, but old legends where see your copy is a death omen. I toyed around with including that aspect, but couldn’t get it to work. The closest thing is that people would call seeing one in its natural form as a death omen. Probably a criminal-only legend since they’d be most likely to fear such a thing.
Want to see a doppelganger in action? Click below: