Need ID help??

[tom's_tank]

Hi I've recently started seeing these worm like things in my aquarium. I don't know what they are and if they are harmful or not? Can ayone help?
Sorry about the bad quality photos its the best I could get.

Thanks!

 

[EeyoreIsMySpiritAnimal]

What is that!! A R2R guide to common new tank hitchhikers.

One of the greatest things about starting a reef tank is getting your live rock in and admiring all the diversity within it. The rock comes to life different creatures. This is a guide that I, along with a very well known critter identifier @KJ , have put together for the new reefer on what...

www.reef2reef.com