Plot summary
The toymaker Winslow P. Schott ( Sherman Hemsley ) gets fired from his job along with his secretary Margaret Duffy ( Isabel Sanford ). Deciding to take revenge, he invents a new toy named "Atomic Space Rats" that includes a substance which when someone is sprayed with, it makes adults act like children and children be greedy. Everyone at the Daily Planet is affected, including Clark, and they start fighting over gifts. Clark realizes that the whole situation has to do with the "Space Rats" and along with Lois they try to find out who is the creator of the new toys.
Their investigation leads them to Schott who gets arrested for his creation but also regrets and makes clear that he cares and loves kids. In the meantime, Superman asks toy store owners to donate toys to the orphanage kids and Lois plans a Christmas dinner for family and friends. All of them though end up having other plans and Lois is alone at her apartment until Clark appears on her door, having canceled his Christmas with his family to be with her.
Credits
Adapted from Wikipedia contributors, Lois & Clark: The New Adventures of Superman season 2. HTML formatting and reference markers removed.