A skunk because it would kill the possum with its stink.
the australia possum
Cats and possums are reasonably evenly matched in their ability to fight and defend themselves against the other. It is highly unlikely a cat would eat a possum, but it might try eating a possum joey. In Australia, possums are at much greater risk from dogs than they are from cats. It is possible, though not likely, that the possum might kill the cat, especially if it is an indoor cat. True possums - those native to Australia - are shy creatures that would rather run from a fight than confront a cat, but they could certainly lash out in self-defence. (Possums are not the same as opossums of North America.)
well possum are nasty creatures so i would say if they are mammals which they are then, yes it does.
This fight would never happen, no matter how you look at it.
carcharodontosaurus would win
An AT-AT would definitely win.
A lion!
The Shark
That would be a battle.
shark
A spartan
lion