So invoking the name of Adolph Hitler has become shorthand for "unimaginable evil," as well as shorthand for dictator ("Grammar Nazi") and even person who I disagree with (Godwin's Law). But was there a "Hitler" before there was A. Hitler?

Was there a single figurehead or even multiple ones invoked to serve as placeholder for "ultimate bad guy" in metaphor? Did someone else serve as a cautionary tale before being overshadowed by the events of WWII? English speaking Western culture is where my curiosity lies, but I'd be interested to know if any other cultures had a similar reference figure as well.

I imagine Ben Franklin writing about how some raucous troublemakers in the Township conspired to rig the voting to name his new beverage "King George did nothing wrong", or people calling each other " Grammar-Huns"