The cloak that made its wearer invisible and gave him the strength of ten men. It was obtained by Siegfried.
From tarnen, "to conceal," and kappe, "cloak."
The mighty dwarf successless strove with the mightier man;
Like to wild mountain lions to the hollow hill they ran;
He ravished there the tarnkappe from struggling Albric's hold,
And then became the master of the hoarded gems and gold.
- Cobham Brewer, E. (2001). The Dictionary of Phrase and Fable. Cassell reference.