The snowbabies might be a symbol of the innocence and beauty of Christmas. 'A pink nightmare' could be a metaphor for something that goes wrong during the Christmas season. In a Christmas story, the snowbabies could start off as the center of a happy, idyllic Christmas setting. But then 'a pink nightmare' could be a series of events like a pink - colored storm that brings chaos. It could be used to show how even in the midst of the joy of Christmas (represented by the snowbabies), there can be unexpected and difficult things (the pink nightmare).
Well, perhaps in a Christmas story, snowbabies could be a part of the festive scene. And 'a pink nightmare' might be an unexpected or contrasting element within that story. Maybe the snowbabies are all white and pure as they usually are, but then something pink and nightmarish occurs, like a strange pink fog that covers the Christmas village where the snowbabies are, which disrupts the normal happy Christmas story.
Snowbabies are often associated with winter and Christmas. 'A pink nightmare' could be a creative and strange addition. In a Christmas story, it could be that the snowbabies are the main characters in a world that is suddenly invaded by 'a pink nightmare'. For example, a little girl who owns the snowbabies has a bad dream on Christmas eve. In the dream, the snowbabies are in danger because of this pink nightmare, which could represent her fears or insecurities during the holiday season.