The best advice I've had about shooting animals is to get down on their level...well, that and use a really fast shutter speed. The shutter speed wasn't so much of an issue with this guy though...
Did you know that underwater, those little guys are friendly and curious.. and actually seem to remember you when you come back to the same reef sometime. They will come up and nuzzle you, and beg for food. Almost like pets!
I did take the pic "just for fun", but also i felt I needed to take a moment and appreciate this guy. The beach was crowded and everytime someone walked by they'd stop and look for a moment, and maybe poke him with their feet or a stick. This way, he's important, even if it's just to me.