Robert,
I have both an Odonus Niger and a Blue Throat in my reef tank. Neither have bothered any of the corals, other fish, snails, or crabs in my tank. I suspected the Niger of eating my Peppermint shrimp because I had not seen them in ages, but found one of the Peppermints alive and well last week.
I agree with Minh. The Triggers he mentioned are as 'reef safe' as they come. The Odonus Niger does get large, but not overnight. You might start with a juvenile and enjoy it for years before it outgrows your tank.
Hope this helps a little. Best of luck with your decision.
-Ed
Custom Acrylic 180g RR, acrylic sump, 45BR frag tank, 18g fuge, 250+/- lbs LR, Euro Reef CS8-2, 10x39W T5, softies, LPS, and a few SPS.