Found this thing with the lights off

[ruegaroo]

I got some new corals today and wanted to check on them after dark and I saw 2 long tentacles flowing around but didn’t see them coming from any corals. I tracked the tentacles and eventually noticed this little guy hanging on the edge of my frag rack and I immediately siphoned him up and jailed him in a cup for pictures. Not sure what it is. I have since flushed him but am worried about the possibility of more of them in the future. Is it some kind of flatworm? It is transparent with 3 spots in the middle of it and it latched on to the bottom of the cup when I had it in there. A little bigger than a grain of rice. Sorry if these pics aren’t good enough they are the best I could get. Any info would be appreciated.

 

[ndrwater]

This is why dipping all new corals is a must..
Not that this guy is necessarily bad, nor good, but always better safe than sorry..

 

[reef life]

Hard to tell from pic, But it could be a Polyclad Flat worm. Nuke it.

 

[Lovemyreef2015]

Looks like it might have been a comb jelly going by your description.