Hard to say but Almost looks like a fire Worm due to the Two lines of bristles on each side and in that case its bad and you need to discard it but im not 100% sure because the turkey baster distorts the pic a little so cant tell for sure. Regardless i would advice to remove it completly from the system
I'd lean closer to it being a bristle worm over a fire worm. While bristle worms are beneficial to a tank, Many including myself strongly dislike them. I wouldn't keep it.