Hello,
I have an Oscar, a salmon tail catfish, a rainbow shark, a black shark and a bristle nose catfish. Most of the time they all get along. Except more recently the oscar has started picking on the salmon tail and the salmon tail is too silly to get out of the way or fight back, even though he is bigger than the oscar. The other fish all know to get out of the way, which I think makes they salmon tail even more of a target. Can you suggest something that might keep the oscar more entertained than bullying the big dopey fish...?

If you have rocks or driftwood or any kind of decorations re-arranging the tank may help. Is there any way to give the cat a place to hide?

The only other thing you could do would be to separate the fish.