Jack frost, the creator of winter.

Once upon a time a long time ago, winter was created. A holiday was created during the winter called Christmas (a story for another time) during the winter, Jack Frost made it cold outside. One Christmas eve, Jack Frost made it too cold for Santa to deliver presents, so Jack Frost became Santana's enemy. Now, every Christmas eve, Jack attacks the workshop and destroys all the presents.

This relates to the Santa's workshop skin contest because Jack Frost is often considered the Arch enemy of Santa. And he often messes up the process of making the toys in the workshop by attacking the workshop.