Originally Posted by Baddog671
Perhaps shiners and minnows, as well as hornyhead chubs (which are a minnow).
Bluegill or sunfish if you have a large tank. They can be incredibly aggressive though, and will likely eat/attack anything their size or smaller.
American Eel would be pretty badass
I kept a few small eels I once netted and they were very aggressive and would swim up the HOB
spillway and make it into to filter. I eventually released them back to where I caught them because they would attack other fish in the tank.