Is this a spaghetti worm?

[aimed]

 

[Anemone_Fanatic]

Looks like it. Personally, I have no tolerance for any worm more than an inch long in my tank, but they are generally harmless detritivores, so it is up to you as to what to do with it.

 

[MaxTremors]

Yes. Completely harmless and beneficial, IMO. They eat detritus and help keep your tank clean.