mission, I believe you've a black sailfin blenny. I've one too and is just like you described. He's quite a character and has even 'attacked' my hand when i've had it in there...including a net. He leaves every other critter in the tank alone, but he does not like anything getting near his 'spot'.
I couldnt make out what you had in the first picture, it was the second one that gave it away. Mine also has those faint blue bars on his face. Sometimes they're more pronounced.
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110g. fish/inverts/sps |