Snail or Slug?

[Marcusa]

I found this crawling around. It looks like a snail that a reddish shell is starting to grow on its back.

Anyone know what it might be?

Thanxs

 

[Brough5754]

Snail

 

[Gubernaculum86]

Looks like a stomatella snail to me. But I've only seen pics. Hopefully someone who's seen one in real life could tell u otherwise.

 

[guarda]

Yes, stomatella. They are awesome beneficial herbivores. I have a bunch and they spawn regularly. That's probably coralline on it's shell. My Linckia is always sucking on them lol.