The mob creeped me out the first time I saw it. I first ran into it in the 3rd room and the mob in the 2nd room didn't appear until a while after, but then it disappeared again. I don't know if that's a glitch or not. The 3rd and 4th rooms seemed to always show the mob. I thought a few of the areas where the noise came up was just noisy and not so much scary, but the first few areas and other ambient sounds did keep me spooked. Well done :)