Strange creature on my aquarium ID please

[MoonHabitant]

I noticed today a strange thing coming out of a rock , it looked at first like a kind of worm but then I’m not sure what is , doesn’t have legs or no hint similar and is hanging from a hole on one of my rocks if anyone can help me with thank you!

 

[WheatToast]

Spaghetti/hair worm. These are beneficial, albeit freaky-looking detritivores.

 

[MoonHabitant]

Spaghetti/hair worm. These are beneficial, albeit freaky-looking detritivores.

Thank you I will leave it alone so