I find it fairly disturbing that a transformation of my precious Kagamin~ into a pig has gained such traction as to make this Butamin figure -- buta being the Japanese word for pig. She's not actually called that, it's just the best name I could think of. The plushie is actually called BuBu Kagabu -- "bu" is the noise pigs make in Japanese.
Made by CharaAni, the plushie will be hitting shelves in June (note: my birthday is in July) for about 2,000 yen. It'd be the perfect addition to your bedroom, as the Butamin plushie is about 7" all around, as all pigs in Japan come in cube form. While it's an odd combination for Kagami, and the implications are none too nice, it's still got a level of cuteness about it.
I didn't notice it over at HLJ or Kid Nemo, two of the regular haunts for importing Japanese stuff, so right now all I can link you to is the shop over at AmiAmi. You've got some time to scrounge up the money for this and to find somewhere to get it, because I doubt these things will sell out like hotcakes.