Zhizhi is a lone mouse in the apocalypse. By eating, it can transform food into a super-strength ability, and by the time it was just one month old, it was already the size of a bicycle. Zhizhi's greatest wish in its entire life as a singleton is to find a male animal suited to it and have offspring. Holding its babies is written into its DNA...
So it turned into a human, and even got a strong, terrifyingly powerful bedmate...