Today my family and I went to the local animal shelter to adopt a cat. Normally I would just get a kitten..but I thought it would be really nice to bring an older cat home before the holidays and give it a second chance. The cat I adopted was the sweetest most affectionate cat..he was playful and when I picked him up he would just lay on my shoulder and purr. I brought him home and he ha been acting ok..walking around openly, eating and coming up to us. I have a female siamese cat..who is about 1 year old and she is very sweet loving..I have never seen her hiss, or get irritated..and this new cat does not like her. He has tried to attack her three times and when I was petting him, I touched his belly and he scratched me. If I pick him up, he growls and hisses. I really really hate the thought of taking him back there..but i want a cat that works well with my family. I have a two year old and I don't want a cat that would attack him. He is acting very territorial and dominant. Any advice? Thank you!