I think that if it does not look monsterous enough it makes it less scary. Being killed by something that is just an object does not generate the same kind of fear even if it is just as dangerous because you intinctually fear being hunted by something obviously predatory. I am not saying to radically change its apearance, I am saying to make subtle changes to make it look more threatening. Make the face a little less abstract looking so that you perceive it as the face of something predatory. I think that all it needs is a more prominent mouth and a few more subtle changes to the overal shape and finer details. Make the facial expression a little less neutral. It does not have to be something obvious like an evil grin or an expression of rage. Just make it look more like something that is looking back at you and is not friendly. Currently its face almost reminds me of the face of the front of a car, which isn't really a face at all, it just happens to look a little like a face because of how parts are positioned.
Let's throw everything in and see what happens!