太空探险家赛门有时露出外星生物，这个叫「阿诺」的心爱小毛怪，长的心爱又和爱，然而赛门的阴险昆季Cecil却把它绑架了，但麻烦的还不只于此，受到进犯拼与钳制的「阿诺」会自愿闹翻，一个变两个，两个变四个，长的又快又阴险，转瞬间镇静小镇斥充阴险小怪物，赛门与「阿诺」要若何赈济小镇？ ......

A 30-something slacker finds his carefree life turned upside down when he falls for his sister's teenage babysitter....