Reminds me of a snakehead I kept years back. That fish would literally eat until it couldn't swim anymore. It would sink with its bloated stomach to the bottom of the tank and just lay on the substrate. My problem with those bass is that even in a 200g tank it's clearly too small for them. That bump on the bottom of his lip is actually from the fish repeatedly banging it off the glass and/or decorations. It can become easily infected and cause the fish to die. You see that a lot in piranha tanks that are too small. If you want a fish that will eat like a beast then you have plenty of options. You could easily house a shoal of piranha in a 120g tank. Don't have to just get the standard red bellies as there are many different species of shoaling piranha (ternetzi, cariba, piraya, etc) pretty much all pygocentrus will shoal. You could get one bad a$$ solitary fish like a black rhombues piranha or one of the serrasalmus species. They'll put that bass to shame during feeding time. SA catfish will literally eat until they can't move but most also get really large. An arrowana would grow large in a 120g and be a ferocious eater. If you like the natural look of the bass look into Gar. They're found in rivers in the southern states, look mean as hell, and are amazing to watch during feeding time. Nothing like watching them sink their teeth into a goldfish as the guts pop out of the eye sockets from the pressure. Good times.