"Twas the Fight Before Christmas" is the second Christmas episode of the Disney Channel Original Series Dog With a Blog, originally aired as part of the network's annual "Fa-la-la-lidays" programming event on December 6, 2013.
When Ellen tells Avery that her sister is coming and how she hates her, Avery decides to set out to create the perfect Christmas in anticipation of a visit from Sigourney's ultra-competitive sister. A series of mishaps take place when Stan invites a stray dog named Sparky to spend the holidays with them.
While Avery, Ellen, and Bennett try to deal with Sigourney, Tyler, Chloe and Stan try to hide Sparky from her. But when he runs away, he walks all over the house and makes her fall on the Christmas tree. Then Avery puts him into a Christmas box with air holes. She leaves it on her bed. Bennett sees it and puts it under the tree.
When they eat Christmas dinner, Sigourney compliments how good Ellen's soup is, now knowing she actually ordered it 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 Christmas at her house isn't perfect. Than Sigourney starts to cry and says that she is lonely at Christmas and that she pretended that she isn't, but she actually wants to have a family. Than they all hug and tell her that she has one.
In the end, Stan writes a blog how Sigourney adopted Sparky and renamed him Snarky.