well, more reading shows the painted frogfish, Commersons, gets to 13 inches, to big for a 30 gallon... So I looked around a little more, and figure a Antennarius maculatus (clown frogfish, or warty skin) which should stay signifgantly smaller...

though, I have to admit, the thought of driving down to corpus and piking one up like rallard, has an appeal. (especially seing how exepnsive the clown frogfish are. (152 at live aquaria. )