l think i know who michonnes pets were. I think they abducted her in the early days and raped her, before eventually being bit by walkers and dying. Michonne took the katana and used it to dismember them (and I bet that if you checked, Michonne would have cut off their dicks) and punished them by keeping them in an extended state of zombification. this event is why michonne is so closed off, and why she was alone. She was probably afraid of other people after escaping, and only saved andrea because she didn't see her as a sexual threat. this could also be a factor in her hatred of merle, who has that whole rapey vibe about him. this will also be a factor in her rekindling her relationship with Andrea after the governor rapes her and she, milton, sasha, and thyreese escape.
what are your thoughts? yell at me in the comments below.