I have opossums in my yard, never had any problem with them. Gentle little (and some not so little) creatures.
Raccoons, on the other hand... I have had them eat spikes. And knock over my bird bath, and make a mess of a little fountain that I grow Phrag bessae and hybrids thereof in during warmer months. I have managed to keep them away from the "water features" with a bunch of bird spikes tied in place to make access unpleasant.