Never kill an Opossum, they eat ticks and such, they are very timid creatures that mean you no harm, they DO NOT carry rabies or other diseases, Ground hogs and prairie dogs can carry bubonic plague, rabies and such. They are the only marsupial native to north america.
Cats do not do well with Australian possums either.
We have a rather large possum that comes around every night and eats all the cat's leftovers....has taken to sleeping in one of the trash cans....I'm still trying to figure out how he gets in there without tipping it over. ???
And yet , cats will attack bears and alligators .
And pitbulls!