Help ID this animal

[kadamik]

This thing is on the back glass of my aquarium. I tried to get a few pics with white lights but it is very small. I would say it is 6 - 7 mm long. It is moving but very slow maybe 1 Cm every 10 - 20 minutes.

THE OFFICE TANK BUILD​

This is a 15 Gallon Innovative Marine Tank that has been running for over 1 month. I have 2 clown fish, 4 Nassarius snails, 3 hermit crabs and soft corals as well as 4 hammers.

 

[Fish Styx]

Hey there. Can you move it to a small dish of tank water and take clearer photos under similar lighting, please. Top and bottom of the critter, if possible.

 

[GSPClown94]

Maybe some kind of chiton but agree with above, better pics will help.

 

[rayadog]

100% looks like a small chiton