Catfish

Catfish are cool little bottom-dwelling swimmers that add something different to your aquarium. They come in all sorts of sizes and species, with unique patterns and those cool whisker-like barbels (the things coming off their heads). Catfish love cleaning the bottom of tanks because they're scavengers, eating up leftover food bits and other gunk. Most catfish are really peaceful, so they rarely butt their heads with other fish or cause trouble (unless your other fish like hanging out near the bottom — then there might be an issue).