It was suggested to me in General Chat that I post this here. All help will be greatly appreciated.

I brought my new kitten home last evening. He is moving aroung the room I have him confined in. He ate during the night and is using his litter box. But he is hissing, growling, and meowing non-stop. He also will lung at my hand if I extend it to him. He was born of a semi-ferral cat in my sister's garage. The mom and now the kittens are being fed by my sister. I have four other cats and do not remember having a new cat so unhappy and I think aggressive. Should I take him back to my sister or will this behavior subside soon. He is 8 weeks old.