I usually end up going to Victoria's Secret during their semi-annual sale, and one time they were giving away these stuffed puppies. These puppies are not squishy, they are very firm.
One day I was sewing, pulling pins out of my traditional tomato pin cushion, and my boyfriend walks over and starts pushing pins into the puppy's head. Why didn't I think of that!? It fits way more pins than my old one, and it gives this silly stuffed animal on my desk a purpose.
I also have some safety pins stuck into his head. (I use them when I thread elastic through a casing)
Im betting this could be done with any really firm stuffed animal. The fabric on the puppy is pretty elastic. When I pull a pin out, there isn't a very visible hole where the pin once was. I'm guessing its plain cotton, similar to quilting fabric.