Please help ID this growth/pest???

[bulldogniner]

Hey guys,

I am not sure what this is growing on my frag plug? I noticed it several weeks ago. It isn’t moving so I don’t think it is a critter but I am not sure. The plug has been in my tank for a year at least so nothing new. No movement but it does appear to be getting slightly bigger. Almost looks like some sort of worm but I don’t see a head either.
Thanks!

 

[Wrassenaround]

Could be a vermetid snail. They have long calcified tubes where the reside. Rarely do you see the snail itself as they retreat back in when danger is sensed. They can be detrimental to corals if they grow on the skeleton near flesh. Had them in my old tank but they didn't do any harm.

 

[bulldogniner]

It doesn’t look like a hard shell. It looks softer like a mushroom almost but not the shape.

 

[tbrown]

That looks like a flatworm....

 

[WheatToast]

Update?

 

[HB AL]

I'd feed it to my fish