Haha, yeah I know. I had some big goldfish that were growing in the pond, and thought I'd see what he'd do. This guy was mainly on convicts, market shrimp, and the occasional pinky. A friend had an african clawed frog infestation, so we used to feed those to him too.
As far as I know, they aren't too hard to breed. You just need to find a pair that are similarly sized or one will get eaten. These things are literally all mouth.