Yellow Watchman Goby
Here is the yellow watchman goby, peering out from behind a rock. This is a typical pose. Unlike the white watchman goby (which is virtually fearless), the yellow is quite timid.
Here is a close-up, where you can see his perpetual frown, and the light blue spots which cover his body.
Another view of the spots, from the side.
A very nice pose on top of a brain coral. Gobys lack a swim bladder, and so usually can be found resting on some surface.