What's this? Yelp.

[miguelarn3]

Somebody can tell me what's this invetebre? How it's named?
It's good for the reef?

https://youtu.be/ywnJ0ZYJwd8

Sorry by my writhing but I'm Portuguese.
Thanks

 

[Betta132]

That's a snail stretching its head out in an attempt to reach a different rock. It eats algae and is harmless to your reef.