Leonard's mother Beverly comes for a visit, and she makes everyone (save Sheldon) miserable.
- The Bully: Beverly makes a habit of killing other people's self-esteem.
- Christmas Episode: The episode is set at Christmas. It begins with Penny and Leonard decorating Leonard's Christmas tree and Sheldon criticising them and throwing shade at Christmas in general.
- Commonality Connection: Sheldon gets along with Beverly just fine as they're both cold, arrogant scientists with a passion for maintaining a belief they are intellectually far superior to others.
- The Dog Bites Back: Leonard gets back at Howard who made fun of him about his mother's visiting by pointing out he still lives with his mother.
- Kick Them While They're Down: Howard joins in on bullying Leonard for the fun of it as his mother arrives.
- Like Father, Unlike Son: Leonard and Beverly have absolutely nothing in common other than that they both wear glasses.
- Mistaken for Gay: Howard and Raj by Beverly.
- Too Much Information: Beverly keeps announcing "I have to urinate" as she assumes anybody wants to know of it.
- The Un Favourite: Beverly considers Leonard the least successful or accomplished of her children. Sheldon mocks Leonard for this.