Appearances in Christmas specials
The Adventures of Jimmy Neutron, Boy Genius
In the series' Christmas episode, "Holly Jolly Jimmy", Libby is first seen taking part in the song "Basking in the Warmth". Later, while she and Cindy are peeking at their Christmas presents, she decides that they should take an embarrassing video of Jimmy to get back at him for telling Carl. While looking around Jimmy's rocket, the girls get trapped in Jimmy's Hypercube, which the boys take with them to the North Pole. Once there, Libby manages to get herself and Cindy out of the Hypercube by turning up the volume on her portable CD player. Libby records footage of Jimmy accidentally scrambling Santa Claus' atoms and putting his Christmas Eve trip in jeopardy, and then give the footage to a news show back home, but as a result of this, she and Cindy end up receiving a lump of coal from Santa at the end of the episode.
Other Christmas productions
Libby also appeared in the Merry Nickmas short "Patrick the Snowman", released as The Adventures of Jimmy Neutron was airing its first season. In the short, she and her friends build a snowman that looks like Patrick Star, which Jimmy then brings to life with his Spoofinator 4000. Patrick proceeds to pester the kids in various ways, including trying on Libby's own clothes.