Help with critter identification

[Wilhelm]

I have numerous pockets and holes in the sand, crushed coral mix at the bottom of my tank. Today, for the first time ever, I saw about half inch of a critter's head. It is black, one eye on each side of the head and had a blue ring around the head just behind the eyes. It had a tiny mouth much like an ell might but not pointy like a Moray. The head and snout appeared round. It looked up to me then ducked quickly down into it's hole. The body is about half the diameter of a common wooden pencil. It poked up several times but would duck down each time I moved to take a closer look.

Help. What is it?

 

[skene]

take a picture...

 

[Wilhelm]

It won't let me. It hates papparazzi.

 

[jdnumis]

try cause that is the only way we can help you id the critter.

 

[Wilhelm]

Mystery solved. Set a trap borrowed from a friend. Don't know how but it is an Engineer Goby. Could a fertilized egg stock to a purchased coral be possible?