Looks like a Citron Clown Goby. They are really full of personality. I love it when they come over and stick to your arm when messing with the tank. They use their Pectoral fins as a suction cup. Great fish for a nano or any tank for that matter.
here's the Black version:
exactly what it is bang guy
he likes to sit on all my corals
he just moves from one to the next and makes a perch
he has white circles on his cheeks like dimples
and he will not get larger than 2 inches
think i will look for another one
