id this slug....

[peckhead]

this tank has been set up for about 4 months now and every day i find something new in it... today i found this thing that looks like a slug or a nudibranch. i took it out because i wasnt sure if it is good or not. any idea as to what it is?
should i put it back in the tank?

 

[peckhead]

the last picture he is kinda upside down.
it has 2 antennas and a little moth like a turbo snail...

 

[m0nk]

Stomatella snail. Free cleanup crew there.

 

[jonthefishguy]

what you have there is a free clean up crew. limpet scientific name:stomatella
you will see more over time....

 

[peckhead]

nice, back in he goes

 

[reefreak29]

Stomatella varia
Classification: Mullusca