Is this a snail?

[TankLife87]

At night I saw this little black blob with a brown line across it.
I think it is a snail out of the shell but not sure.
If it’s not what is it and what do I do.
If it is, should I get some larger shells or somthing for it to find a home?

 

[reef lover]

Scutus Elephant ear snail...super neat..may feed on sps if you have them.

 

[Retro Reefer]

Snails don’t leave their shells, looks like a black Nudibranch.

 

[reef lover]