My clues (aside from noting where it comes from):
Kittykat had suggested Neogobius, so I said "I think you need to go less new and more small on the genus Kittykat. " So, remove "Neo" (new) from Neogobius, and replace it with "Micro" (small) to get Microgobius
"I could give the species name, but that would be being greedy." gulosus is Latin for greedy.
"What sort of clown do you take me for?" One of the common names for Microgobius gulosus is Clown Goby.