What is this Octopus leg looking thing

[KQuillan]

I have seen this thing once before and when I tried to grab it, it scurried back under the rock. It has a few legs and I have no idea what it is. It is living under the rock. Tried to get the best pic I could and a small video which may be a bit better.

 

[RobinC]

Micro brittle starfish best guess. Lucky....looking for some too!

 

[KQuillan]

Micro brittle starfish best guess. Lucky....looking for some too!

Thank you!

 

[WheatToast]

Micro brittle starfish best guess. Lucky....looking for some too!

+1
Good detritivores.

 

[Afkomjorgen]

Agreed, micro brittle star. Excellent cleaners!