I have catmint growing out in the garden and I chew on the leaves all the time. I swear it has never made me ferocious, but I will just assume it affects people in different ways.
The Herb Of Ferocity
If you have any reason to suspect that you are too mild mannered, too gentle for this strenuous age, eat catmint. Miss F.A. Bardswell in her book “The Herb Garden” says catmint, one of the ten varieties of mint, is known as the herb of ferocity because of the ferocious disposition it imparts. “The herb when chewed,” says Miss Bardswell, “is said to make the most gentle person fierce and quarrelsome. A legend is extant of a certain executioner who could never muster up his courage to the point of hanging till he had partaken of it.”
Source: Bryan Daily Eagle And Pilot. Newspaper. May 08, 1912.
