ID crazy thing in refugium

[myownlife]

Just turned on my lights and saw a creature I've never seen before. It was about an inch long half inch thick. It looked like a snail but had no shell. Right when the lights went on it hide quickly and moved really fast. Wasn't able to get a pic. Any ideas. Looked like a slug

 

[ahtatt]

stomatella snail?

 

[declanisadog]

stomatella snail?

This. Harmless and a good cleaner