Newbie with a molusk Question

[frozen up north]

I was gazing dreamily into my 10 month old 77gallon tank when I saw the thing, I went to get my camera and of course it was gone. I remember learning about them in high school biology class. It was a Chiton. Can anyone tell me if they are a friend or a foe? Do they cause problems for other inverts?

Thanks for your help.

 

[Julio]

Does it look like a cone snail?

 

[mbbuna]

chitons are ok

 

[frozen up north]

Do you know what they eat, how big they get, if I have one is there more? I think its really cool, its pink.

Thanks