Weird Tentacle In My Coral

[Zortru]

There is this really weird tentacle near my coral, its at the base of it and it's kinda collecting rocks, anyone can explain what is it and why its doing this?
I made a video of it to help, here the link to it

 

[Sniperhank]

It's a worm that the name is escaping me right now. They are harmless.

 

[bribo12]

Spaghetti worm


Sent from my iPhone using Aquarium Advice

 

[Zortru]

thanks for the help