The Blood Eagle was an unimaginably gruesome form of torture and execution practiced by the Vikings. According a Scandinavian document, the ßáttr af Ragnars sonum, it was used on the king of Northumbria after the defeat of his forces during the Viking invasion of 865. Here’s what they did:
‘They caused the bloody eagle to be carved on the back of Ælla, and they cut away all of the ribs from the spine, and then they ripped out his lungs.’
Scholars dispute whether Blood Eagles were ever actually performed; it could be a myth based on misinterpretation or mistranslation of Viking poetry.
Still, it’s pretty disgusting.