This is Kaiser Karl, named after Karl Lagerfeld. I am not exactly sure how old he is, but I have had him since March. This is Karl's story:
My former room mate and her boyfriend had a mutual friend that wanted a pet. They all went to a local pet store and went over to see the mice. There were two cages, and Karl was isolated from the other mice in the second cage. The friend asked why he was separated from the others and the owner of the store told him that the mice were being maimed and they had narrowed down the bully being Karl. The owner said he would give Karl away for free and all he had to purchase were the necessities. This irresponsible boy did not know what he was getting himself into, and a month later he was pleading my room mate to please keep Karl (which he had named Achilles the warrior). The day that he had bought Karl they had brought him over to our apartment and I had held him in my hands. I had never handled a mouse, but I thought he was the cutest. My room mate asked me if we could keep him and share custody, and I agreed. I renamed him Kaiser Karl because of his black and white fur, reminiscent of Lagerfeld's white hair and all black outfits. Plus Karl was very stand-offish and did not like to be held, and he would obsessively clean himself after any human contact. I liked imagining Karl having a thick German accent and being very critical. 2 months later my room mate and I were going our separate ways, and she was moving back home where she has younger siblings and in her own words, the kids would kill him. Now Karl is my one and only, but since he has such a violent past with other mice I am afraid to buy him a buddy. He seems to be very happy being alone though and I try my best to entertain him and give him as much time out of his cage as possible. I would love to have another little one though! Have any of you had a bully and have successfully introduced a cage mate?