There have been at least a few threads on this, some with some pretty good info.

Lots of places use the name for some small catfish, but the specific catfish varies from one locale to another in "vernacular" usage. The big guys responsible for proper naming of stuff restrict their usage to one - or a few - specific varieties of catfish; but hardly anyone else pays much attention to them.

For practical use here, I'd say it's that critter jumping out of the banjo at the top of the page.

John