Fixed the photo for you, so it'd show up.
It's a flatworm, I believe, though it looks different than Red Planaria (which isn't always red) and doesn't look like an Acro Eating Flatworm. There are numerous species of flatworms, that are completely harmless. I'll move this to a more appropriate forum and hopefully Leslie will chime in soon. She's our resident Worm Guru. Well, not so much residential, as she's a world renowned Worm Guru!!