What on earth was that 'thing' on the ground that made Bob scared?

I haven't seen this movie for a while, but I've been IMDB'ing it tonight because I remembered how gory and disgusting it was - perhaps the only film that has ever made me feel physically sick.

I randomly remembered a scene which bugs me a little. I think it's near the beginning where Bob? starts messing around with that blow-up doll and then suddenly he spots something on the ground which makes him groan with terror. It looks to me like some sort of... baby corpse covered in maggots? That's just something so disturbing that I can't get my head around it.

Is that what it was supposed to be?