Hi and welcome to HC!!! Congrats on giving your darling Casper his loving, forever home with you. It's a shame that brother didn't bond well with him, but luckily Casper has you to really love and care for him. I am glad that he is settling in so well, and I hope that the two of you have tons of fun together. I am not sure if there is a slight hue of cream on his coat, but it does look like there is in the first picture. If so, I believe that he is a short hair, cream banded hamster. He is absolutely handsome and I love his bright, ruby red eyes; they are very striking! I also love his name, too; he does look like Casper the friendly ghost, lol.
He looks similar to Rad's Syrian hamster Ghost.