"Aggressive 'possum"? In my experience no such creature exists. Opossums are by nature peaceable creatures and are utterly incapable of aggressive action. They also cannot carry rabies. I don't know how you define aggression, but I've yet to see a 'possum do anything except scurry away, go limp, or slobber profusely in response to my presence.
Opossums are beneficial creatures and are harmless to humans, property, and livestock. Please don't stomp them!
Well it seems that there are TWO of us at least that know the 'Possum will not actually attack.
However, it will show it's teeth and make a gawd-awful hiss when it feels threatened. Most people have assumed that the 'possum is going to attack them, and dispatch them right then and there.
But my point was, that most people wouldn't care if he had stomped a 'possum. They are rather ugly and nasty looking, my wife calls them giant rats, and they do resemble that remark.