Slug??

[mz3bmx]

I purchased a mushroom frag and xenia and noticed a few creatures pop out when the lights went out. On the mushroom is this slug looking creature. Good or bad?

On the xenia there's a worm roughly around 5in slithering its way throughout the xenias. It's hard to get a shot because every time it sees me he makes a run for it. Any takers on what this may be?

 

[keri]

#1 Stomatella snail (tiny shell on back) Great pic! Beneficial
#2 probably a bristleworm, can't tell, not a bad thing. HTH

 

[bang guy]

I second the IDs.
On the worm, keep an eye one it. Out of 10,000 species of Bristleworm, less than a dozen can eat coral. Your worm looks like it could be one of the odds breakers - Eunicid.
I wouldn't panic, just observe your Xenia for missing pieces.
If you ever get a good shot of the head post it and I can give you a better ID.

 

[cranberry]

I agree that I would watch that worm.

 

[mz3bmx]

Thanks guys and I will definitely keep an eye out on the worm.