My 1 and 1/2 year old cat Willy has been eating clothes, fabric, any type of material and stuff. He has eaten many wool sweaters, socks, t-shirts and also had chewed up old stuffed toys. And when you try to get it from him he growls and hiss' at you. I asked the vet but he said that it is very weird for cats to do that.

Is there anything I can do to stop him from ruining everything and making himself very sick?