Cloak of invisibility

Cloak of invisibility
Alberich puts on the Tarnkappe and vanishes; illustration by Arthur Rackham to Richard Wagner's Das Rheingold
Plot element from Folk lore and fairy tales
First appearance	Ancient
Genre	Folklore and fairy tales
In-story information
Type	Magical cape
Function	Renders the wearer invisible

A cloak of invisibility is a fictional theme and a device under some scientific inquiry. In folklore, mythology and fairy tales, a cloak of invisibility appears either as a magical item used by duplicitous characters or an item worn by a hero to fulfill a quest. It is a common theme in Welsh and Germanic folklore, and may originate with the cap of invisibility seen in ancient Greek myths. The motif falls under "D1361.12 magic cloak of invisibility" in the Stith Thompson motif index scheme.

Cloaks of invisibility are magical items found in folklore and fairy tales. Such cloaks are common in Welsh mythology; a "Mantle of Invisibility" is described in the tale Culhwch and Olwen (c. 1100) as one of King Arthur's most prized possessions. The mantle is described again, and in more detail, in the Breuddwyd Rhonabwy, and is later listed as one of the Thirteen Treasures of the Island of Britain. A similar mantle appears in the Second Branch of the Mabinogi, in which it is used by Caswallawn to assassinate the seven stewards left behind by Bran the Blessed and usurp the throne.

In the English fairy tale Jack the Giant Killer, the hero is rewarded with several magical gifts by a giant he has spared, among them a coat of invisibility. Iona and Peter Opie observe in The Classic Fairy Tales (1974), that Jack's coat may have been borrowed from the Tale of Tom Thumb or from Norse mythology, but they also draw comparisons with the Celtic stories of the Mabinogion.

The counterpart in Japan is the kakuremino (隠れ蓑^?), a magical "straw cape" or "raincoat" of invisibility. In the folktale of the "Peach Boy" Momotarō, one of the booty the hero collects from the ogres is a cape of invisibility, paralleling the story of Jack the giant-slayer.