image from Undine, by Friedrich de la Motte Fouqué
illustrated by Arthur Rackham
The use of magical clothing for traveling purposes is a common theme in many cultures. In Taiwanese folklore, the ndejeni is a creature that helps fishermen by submerging in the ocean with the help of vests… Similarly, in the folklore of southern, and south-eastern Ireland merrows (fairy-mermaids) wear a small red cap made from feathers, called a cohullen druith, which they use to propel through the water… in Faroese, Icelandic, Irish, and Scottish folklore… the selkieare seal people that are able to shapeshift into humans by shedding their seal skin…
This motif of transformation through skin coats is found throughout the world… the Russian swan maiden, the Croatian tale of the She-Wolf… the Native American (Lakota and Sioux) myth of the White Buffalo Woman, the Japanese legend of Hagoromo…
Clothing has existed for as long as humans have, and is older than language itself… The narrative of supernatural beings using magical clothing reflects our own human society, where clothing is a reflection of our inner psyche.
(extremely abridged—read the original post, plus footnotes, at Culture Potion)