- "I read 'Pet the Bunny' before I could walk"
- ―Library Kid
Library Kid is a student attending Third Street School, who spends all her time in the library.
Library Kid is a timid and intelligent girl who spends all her time in the library. She is intelligent and a linguist. She can speak French, German, Greek, Latin, and Basque apart from English. When she likes something, she tends to go overboard and over-commit. This was first shown when she locked herself in the library every day due to her love of books, and then went crazy when she grew to love recess, swinging and playing everywhere. Eventually, Gretchen taught her to enjoy things in moderation. She seems to look up to Gretchen as a big sister.
Library Kid is short and skinny with pale skin and square magenta glasses. She has medium-length reddish-brown hair, a lavender T-shirt, a dark purple skirt, white socks, and black Mary Jane shoes. Like Gus, she's drawn with the black bead eye style. When Gus pulled the book out he saw a white eye with a black pupil staring at him, which was the Library Kid's eye.
Ever since she could remember she loved books, she read "Pet the Bunny" before she could walk. when she began kindergarten, she was excited at the prospect of discussing her favorite books with her peers. She was shocked to see that the kindergartners, unlike her, were loud and dirty. She ran out of fear and entered the library. She had been spending her time in the Library until she was approached by The Recess Gang, who thought her a 'wild child' until she addressed she was a linguist. When they introduced her to recess, she began to go crazy due to her excitement of being outside, to the point where they had to bring her back into the library. Near at the end of the episode she’s seen outside jumping rope with The Ashleys while Gretchen watches her from outside Miss Grotke’s classroom window.
- Despite appearing jumping rope with The Ashleys in the epilogue, Library Kid's real name has never been mentioned. Fans speculate that her name is also "Ashley" though it was never revealed in later episodes.