What is this?

[patgrandprixgrl]

Hi everyone,
I got home today and noticed a couple of these creatures on my glass. Are they good or bad?

 

[BL1]

I believe it's an asterina star but I could be wrong ...
Asterina Starfish - Invertebrate Information Database - Nano-Reef.com

 

[yote]

BL1 is 100% correct.

 

[patgrandprixgrl]

Thank you for info...
Oh, Boy. My snail ate one.

 

[Bifferwine]

Yep, asterina star. I have tons in my tanks.