We have a green coral goby. He started off in the 100g but our Algae Blenny hated him with a passion and would constantly chase it. We moved him into our 58L nano and then into out 120L Cube.
I would post a photo of him but we hardly ever see him. He darts out for about 3 seconds at feeding time then disappears into the rockwork again. Its a shame because he is a very pretty fish with really nice markings.
Ours eats everything we put in the tank.