I have a Large Mouth Bass that I caught in a nearby river, in August. He was about six inches, now he's more than double that in length. This is him about two months ago, with a goldfish in his mouth.
I suspect that he's about a pound now. I've been keeping him in a 29 gallon, but he's outgrown it. I just ordered a 125 gallon for his new home, but I suspect he'll eventually outgrow that.
Just to keep the water clear requires almost daily water changes (2-5 gallons). He'll eat a dozen large feeder goldfish in several days. I used to have about 15 assorted green sunfish and pumpkinseed. The largest two are all that are left. The last one he ate was so big that the tail hung out his mouth for two full days while he digested the head. I wish I had taken a picture of that.
He was skittish at first, but now he's real sociable. He'll come up to the front and look at me for as long as I sit there, and if I walk in the room with a white bag from the local fish store, he knows he's about to be fed, and starts dancing back and forth. Feeding is hilarious, if he's gone a few days without any. He attacked a gold fish so fast that he created a wave and the goldfish ended up on the floor.
He likes to chase the larger green sunfish around, but he leaves the catfish alone. He's eaten every crawdad I put in there, too.
Like someone else said, if you like native fishes that feed agresssively and are very active, I'd start out with a green sunfish. They'll eat flake food, as well as just about anything alive that they can fit in their mouth (and they will try to eat things that are too big, which is hilarious). They also eat each other, so I only keep similarly sized ones now (although I catch smaller ones to feed the Bass). They don't get huge, so you can keep them in relatively smaller aquariums. In nature, it's not uncommon to find them stunted in small ponds with limited food supplies, so I suspect they won't outgrow too fast as long as they aren't overfed. Like others have noted, I would not use an undergravel filter, because they like to dig.