What is this?

[demonspeedn]

I found this slug type critter as I was cleaning my refugium.

 

[demonspeedn]

Turn the sound down, pumping water is loud.

 

[SandJ]

Chiton, they are good critters.

 

[demonspeedn]

I thought Chitons had hard shells?

 

[saltyfilmfolks]

https://en.m.wikipedia.org/wiki/Chiton

 

[reef lover]

That's a pretty one!

 

[cristata.reef]

Yup Chiton, genus Cryptoplax

 

[Lovemyreef2015]

Cryptoplax larvaeformis (chiton)

 

[demonspeedn]

That would be it.
I've seen "regular Chitons" in my tank, but nothing like this.
Thanks for the positive ID!

 

[KJ]

Cryptoplax larvaeformis (chiton)