Introduced as a PC race in the excellent Dragon Empires Gazetteer, blown out in the Advanced Race Guide, and finally statted up in the Bestiary 4, wayangs are creatures of shadow inspired by Javanese shadow puppets.
What do you need to know about them? First off, ignore the illustration in the other books and check out the one in the ARG. The strange, almost two-dimensional figure barely looks like it belongs in Golarion, doesn’t it? That’s not a criticism—that’s a compliment. Wayangs are meant to be otherworldly, meant to be alien—in fact, the DEG notes that they are creatures from the Plane of Shadow stranded on the Material Plane—and their oddly proportioned portrayal in the ARG underscores that notion fantastically.
It gets better: Wayangs resent the world they find themselves in. They come from a culture that “idealizes a shadowy state of nonbeing.” (I cannot tell you how much that excites my inner Williams College Religion 101 student.) Oh, and they can choose to swap how positive and negative energy affects them for one minute. Just because. That’s amazing!
Like tengus, wayangs are a race that, were I starting a campaign today, I would almost certainly include in the setting and would seriously consider making a core PC choice. How better to say, “This is my world”? How better to escape the nearly inexorable gravity of Tolkien or the Realms? And don’t get me wrong, I love fetchlings—I’m still very proud of my entry on them—but wayangs are by far the more evocative shadow monster. And in terms of worldbuilding, I keep mentally slotting them in to see how they upend my default settings (pun!). What does a campaign look like where wayangs are your halflings? Your gnomes? Your gremlins? Your goblins? Your elves? And while Golarion’s wayangs tend to be reclusive jungle dwellers, yours might be hiding right in the shadows of your campaign’s largest city.
In a hobby that treats dwarves and elves and dragons as perfectly ordinary, wayangs are still fantastic and strange in the best ways. If you haven’t already, definitely check them out.
The wayang Waskita the Quick is more than just a rogue-for-hire. He has a particular specialty: He is a cleric killer. He uses his mastery of shadow magic to strike at his victims from concealment while mimicking one of the undead. Should he get bogged down in combat, careful use of his light and dark ability ensures that channeling attempts meant to strike him down only bolster him instead.
Jungle-exploring adventurers come upon a small wayang nation in a state of upheaval. Proselytizing outsiders promise a return to the Plane of Shadow—the dream of many a wayang. But the evangelists are kytons in disguise, and the home they offer is a realm of torture. Worse yet, even if the kytons are exposed for what they are, some wayangs’ yearning for the Plane of Shadow is so great they would offer up their own people into slavery.
Females are not allowed onstage in Dessex, as the puritan Cardinals of Might deem their presence too provoking. The one exception is the popular art of shadow puppetry, long the specialty of the nation’s wayangs. Now the Cheapside district’s shadow puppet theaters are becoming hotspots for actresses, dramatists, suffragettes, revolutionaries, and all kinds of shady folk—literally and figuratively—who wish to see the Cardinals toppled.
—Pathfinder Bestiary 4 274
Way more about wayang (the theater, not the monster) is here.
I also owe Williams for my knowledge of Restoration theater, which comes into play above. Any era that returns women to the stage and where pox and venereal diseases are so prevalent that wearing patches becomes a fashion statement is an era worth exploring.