For me, I picked mouse for several reasons. I always enjoyed books, cartoons, and movies that featured mice or rats as the main characters. I heavily enjoyed the Redwall series during my childhood, as well as cartoons and movies like Tom and Jerry, the Secret of NIMH, and the American Tail movies. I always saw myself in many of the mouse characters and could relate to their struggles. Another reason is I always mainly pick the smallest race/species in the mmos I play, such as the Tarutaru in Final Fantasy XI and the gnomes in World of Warcraft, because they typically have the cutest looks and I enjoy having a cute little person taking the front lines and having a small tank to take the blows and protect others. Being a manly muscular big guy just isn't my thing.