Please don't be so mean. As you can see I have this tank for just one week now. Not everyone is so smart as you are, and not everyone knows all the worms names and if they are good or bad.
I came to this forum because they have recommended me, they said I can find answers to all my questions no matter if they might sound stupid for some of the users.
It's a Bristol worm. Not bad but don't touch it with your hand. I personally remove these if I see one slip by but it won't bother anything.
On a side note, keep asking questions and read anything you can related to this hobby. It's the only way to learn. Keeping a reef is a never ending learning process...
Thank you so much for your answer Tahoe61. I will check right now these links and I will write down a note for my next shopping tour to the Aquarium shop to not forget the magnifying glass. :*