Got a bunch of euphyllias and this morning this giant flatworm thing is here

[Shawcabelguy]

An idea what this is on gonna take it out either way

Finger in there for size comparison

 

[EricR]

I know nothing but definitely pull it out. (Don't think anyone ever "wants" any type of flatworm, even less harmful ones).
Picture from above in just enough water to submerge it would probably help experts ID.

 

[Kristopher Conlin]

Looks like Euphyllia eating flatworms unfortunately. Are they in your main display? Or in a quarantine tank.

 

[Kristopher Conlin]

Here is a good article about them

Watch Out for a New More Damaging Euphyllia Flatworm | Reef Builders | The Reef and Saltwater Aquarium Blog

Coral pests are pretty much a fact of life for any reef aquarist or coral gardener, and these parasites and diseases range from slightly irritating to downright lethal. Recently we documented our…

reefbuilders.com