If your wondering, it is because I am of mixed heritage (half White/half Hispanic) and as I'm proud of them bdth, it seemed wrong to favor one over the other in the ethnicity choices.  I have found that, many times, in the answers given for questions like that, they never offer the answer I like, so I usually put "Other".  Also, "Undead" seemed like a good way to point out the fact that I'm decidedly not what society thinks I should be:-)