Pandrosos (also known as Pandrosus) is known in Greek myth as one of the three daughters of Kekrops, the first king of Athens, along with her sisters Aglauros and Herse. The three of them together are often referred to collectively as the Kekropidai after their father.
Kekrops is thought to have been born from the soil of Athens itself, and possesses the head and torso of a man and the lower body of a snake. Beyond his status as Athens’ first king, he is known for judging the contest between Poseidon and Athena that decided the naming and patronage of the city. However, following his death, Kekrops is not succeeded by his son, but rather by Erechtheus (also known by the name Erichthonios), the child of Hephaestus and Gaia.
As told by the Bibliotheca, the god Hephaestus, in a fit of passion, attempts to rape the virgin goddess Athena, but is unsuccessful. In vain pursuit, he ejaculates on the Acropolis, and his seed fertilizes the soil there, impregnating Gaia and leading to the birth of Erechtheus. After Erechtheus is born, Athena takes the baby into her care and places him into a chest (or, in some versions of the story, a basket). She entrusts the chest to the Kekropidai, warning them never to look inside.
While Pandrosos faithfully follows Athena’s instructions, Aglauros and Herse are compelled by curiosity to open the chest, provoking Athena's wrath. The two disobedient sisters are driven mad when they see the contents of the chest (in some versions of the myth, they see Erechtheus being guarded by a giant snake; in others, they see Erechtheus himself in the form of a snake), and hurl themselves off of the northern slope of the Acropolis, falling to their deaths. As the dutiful sister, Pandrosos is spared her sisters’ unfortunate fates.
There are several other versions of the myth of the Kekropidai. They generally disagree with one another on the topic of which of the sisters carries the blame for opening the chest. In one version, all three sisters are equally culpable, and Pandrosos succumbs to the temptation to look inside the chest along with her sisters. Another version of the myth holds Aglauros and Pandrosos as blameworthy, with Herse taking on the role of Pandrosos as the innocent sister. Yet another version tells the tale that Aglauros alone opened the chest, and that Pandrosos and Herse were spared Athena’s wrath for dutifully following the goddess’ instructions.