Invertebrate ID Please

[Yeos87]

I found this black shell less slug in my tank, not sure where it came from. But I want to see if it’s a good or bad hitchhiker before I remove it. Here are some picture listed below. Thanks in advance.

 

[Reefer Reboot]

Looks like an Elephant Slug.

 

[Clarkjw2002]

Stomatella snail. Good hitchhiker. Algae eater.

 

[Yeos87]

Thanks guys.

 

[Reefer Reboot]

Does it have a small cap shell on it's back?