They have sharp teeth and crushing strong jaws. Further they are tough, kind of like a football partially inflated with water and chicken bones - and they're just too stupid to know they are dead.
I've dispatched plenty of possums with my trusty Swiss army knife, generally at 2:30 in the morning when they've managed to get into the pigeon coop, and believe me I'd rather not. The carbine would be a lot safer but it tends to disturb the neighbors more.
In any case, it is illegal to be a possum in the state of California.
Swiss Army knife.
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