Ruble is a russian blue dumbo.
Ruble came to me with his brothers, Kingdom and Taiga. See Kingdom's page for their story.
Ruble is the alpha of the trio, and can be a little tricky when it comes to introducing him to new rats. He does eventually accept them without any real issues, but it does tend to take him a while to get to know another rat, and he can be a little unpredictable with them until he does so.
Why Ruble? I wanted a Russian name for Ruble, given that he was Russian blue. A Ruble is the Russian currency.