After Peggy the pug puppy is left at the animal shelter just before Christmas, she is taken in by a foster family. But the situation is just temporary--the family isn't ready for a dog quite yet. And the little girl, Chloe, wants a unicorn for Christmas, not a puppy.

Peggy decides that she will become a unicorn to make Chloe's Christmas wish come true--and hopefully make Peggy's temporary home her forever home in the process. All she needs is a long silky mane, a glowing horn, and the ability to do magic! Easy-peasy, right? But all of Peggy's attempts to become a unicorn go hilariously wrong. From knocking over the Christmas tree to getting lost in the snow, Peggy remains a pug. How will she ever find a forever home if she can't make her new humans happy?