:happyfish Looks like an eel or a type of gobie like the engineer family of gobies possibly. Good luck, doesn't look reel nasty so I wouldn't worry too much.
Does it have teeth that protrude?
:happyfish probably some sorta worm then, not an eel, not a gobie. Really big for a worm though. If it has claws that bend backwords like a praying mantis insect, then it's a mantis shrimp. Good luck, ali