I have not had one in my tank. According to "Marine fishes"
They get to be about 11 inches and can eat small clams and
shrimps,crabs, hermit crabs.
This is a quote from the behavior section
" Can become aggressive, towards its tankmates especially
smaller fishes. It will grasp an elongate prey fish in its jaws
and bash it against the substrate until it breaks into bite-size pieces"
Good book I highly recommend it.