Million Dollar question.........?

What about a mantis shrimp? Out of what you listed the only other thing would be emerald crabs...they can wreck havoc sometimes... maybe try putting them in the sump for a few weeks and see what happens.


from LA's Emerald Crab description:

Care needs to be taken to ensure an ample supply of food is available for the Emerald Crab. Many aquarists supplement the Emerald Crab's diet with dried seaweed and chopped meaty foods, such as shrimp, as well as a quality pellet fish food.

Otherwise, this opportunistic feeder may turn to corals, invertebrates, or small fish for a food source. However, when well fed, most Emerald Crabs are very tolerant of their tankmates and highly compatible in reef environments. Like other invertebrates, the Emerald Crab does not tolerate copper-based medications or fluctuating water parameters.

 

Emerald Crab was my first guess Too!

 

I've watched emerald crabs rip zoas right off the tile to get to the algae that was growing around them.