Worm Thing

[Tito2491]

I woke up at like 1:00 am yesterday and i turned on the lights of my 37 sw aquarium and i saw a little worm like creature , about 1 cm long . It stuck to the glass then went got sucked into the powerhead . What Could It Be???

 

[TCTFish]

A picture or more detailed description is needed. Does it have spines? What color is it? Is it segmented?