Looking for some help on this ID. I think it a Gulf Killi. I originally put him in a tank with Darters, Shiners, 1 Blackstripe Topminnow and 2 Northern Studfish but the Studfish picked on him. Weird, the Studfish have not been aggressive towards any fish before this interaction. All is good now.
My kids netted the same thing. Its in a tetra tank with a bunch of cory cats, a synodontis (yeah, he doesn't belong but it works), and a dojo. Seems to hold his own and eats like a pig.