I would have to say a Midas, but I am biased. I have seen a Midas beat up a Red Devil here at a local shop. The Midas was 10" and the Red Devil 11-12".
Actually, my Midevil does great with a common Pleco (who is same size as RD) in a 65g, he bothers him sometimes, but the Pleco is a tough nut.tlt77;4560700; said:putting anything in with a red devil that size in a 60 gallon tank will most likely end up dead