Rocket cats? As weapons?

Apparently yes. A 16th century German war manual appears to show jet packs strapped to the backs of cats and even doves, with the text advising military commanders to use them to "set fire to a castle or city which you can't get at otherwise," The Associated Press reported.

University of Pennsylvania researcher Mitch Fraas is trying to unravel the mystery behind the documents.

"I really didn't know what to make of it," he told the AP. "It clearly looks like there's some sort of jet of fire coming out of a device strapped to these animals."

Don't fret, animal lovers.

It doesn't look like any cats or birds were ever used in the way artillery master Franz Helm described 500 years ago.

"Sort of a harebrained scheme," Fraas told the AP. "It seems like a really terrible idea, and very unlikely the animals would run back to where they came from. More likely they'd set your own camp on fire."