In-game, the mumblers always reminded me of teddy bears with big claws..
I felt the same way! When I first played and saw the teddy bear like creatures, I was far less scared, (though it made the whole, looks like they're humping your leg attack animation so much easier to accept aha).
I think the whole idea and concept of children attacking you as deformed creatures is far scarier, movies get away with far worse than pixelly grey blobs when they're beating the ghostly child/creature child trope, so I always found it ridiculous that Sh1 had been censored in that particular area. The age old argument of whether it's ok to kill children in video games is a tender subject, but nobody can deny that the whole concept of the grey children is so much more scarier.