Introduced in—what? X1: The Isle of Dread? AC9: Creature Catalog? Who knows? What matters is their reinvigoration at the hands of Bruce Heard’s “Voyage of the Princess Ark” series—in particular the installment from Dragon 183, which introduced the aranea wizard nation of Herath. Before merely brainy, weakly spell-casting spiders, in that article aranea became shapeshifters and a worthy NPC (or even PC) race—and should still be considered so (even if the art in the Bestiary 2 does them no justice). Also, as Neutral creatures of scholarly bent (and more likely to ransom than kill), they can be a good reminder to PCs that ugly or deceptive does not equal enemy…unless it does.
For years, a colony of aranea has masqueraded as a clan of elves. Eventually, their arachnophilic ways arouse the suspicion of their true elven neighbors, who mistake them for drow. As arrows and spears are sharpened, one scholar among the elves preaches peace—but as a nearsighted, stammering half-breed, he makes a poor interlocutor.
In the gondolas of the canal city of Pencia, merchant lord Carlo Correr is called “the Spider in the Tower,” as from his perch in his cupola he seems to know everything that transpires in the city. The name is all too apt—Correr is an aranea who facility with charms and hunger for information are unmatched.
The halfling nation of Lucerne and the aranea principality of Brynn keep an uneasy peace. Adept at spotting aranea in humanoid form—and even more adept with their slings—Lucerne’s rangers have exacted a promise that no aranea from Brynn will ever take halfling form again, on pain of death. Such a pledge was necessary after Brynn’s last attempt at usurpation and occupation.
—Pathfinder Bestiary 2 30