might be a flatworm, never seen any pics of ones like this
clearish body, whitish head, yellowish stripe in center of body(cant tell if pigment or seeing the guts through the body) about 1/4 inch to 5/16 long
traveling on glass sometimes when it turns around it picks up its head and does a 3d u-turn if that makes sense-doesnt lay flat which I've never seen a flat worm do.
also that tail/appendage at the rear doesnt look flatworm to me