When Ellen tells Avery that her sister is coming and how she makes her cry (as she thinks she is better than Ellen) Avery decides to set out to create the perfect Christmas in anticipation of a visit from her ultra-competitive Aunt Sigourney- Ellen's sister. A series of mishaps take place when Stan invites a stray dog named Sparky to spend the holiday with the family.
While Avery, Ellen, and Bennett try to deal with Sigourney, Tyler, Chloe, and Stan try to hide Sparky, from meeting with aunt Sigourney. But when Sparky runs away, he walks all over the house and he made aunt Sigourney fall on the Christmas tree. Then Avery puts Sparky into a Christmas box, with holes for air. She leaves him on her bed and when Bennett sees it he puts the box under the tree.
When they have a christmas dinner, Sigourney compliments how good is Ellen's soup, that she actually ordered from the restaurant. When Bennett brings chicken to the table, it starts to move and Sparky comes out. Than Ellen starts to laugh and says that the christmas at her house isn't perfect. Than aunt Sigourney starts to cry and says that she is lonley at christmas and she says that she pretended that she is not lonley, but actually she wants to have family and christmas. Than they all hug and tell aunt Sigourney that she has a family.
In the end, Stan writes a blog how aunt Sigourney adopted Sparky and renamed him as Snarky.
- G. Hannelius as Avery Jennings
- Blake Michael as Tyler James
- Francesca Capaldi as Chloe James
- Stephen Full as the voice of Stan
- Regan Burns as Bennett James
- Beth Littleford as Ellen Jennings
- Cynthia Watros as Aunt Sigourney
- Bennett: Wow, this is a really bad invention. Who would buy this?
- Avery: What's so bad about aunt Sigourney? I bearly know her.
- Chloe: That's believeble?!
- Stan: Well, that's the bathroom, but for some reason people go inside the house. What Animals Would do that?
- Avery and Ellen: We, will win. We, will win!
- The episode's title is a pun on the popular storybook saying, "Twas the Night Before Christmas".
- This is the last episode that will premiere in 2013.
- This episode is similar to a good luck Charlie episode when Bob’s mom comes over for Christmas and Amy like Ellen does not get along with the other person so Amy as a way to cope (saying Apple whenever she is irritated)
| To view the Twas the Fight Before Christmas gallery, click here.