Charles Schulz introduced Charlie Brown's pen pal concept to Peanuts on August 25, 1958. For 36 years, readers never saw the pen pal's face. On September 27, 1994, Schulz revealed the character was a Scottish girl named Morag who wrote in a phonetic accent. Charlie Brown fell for her immediately, only to learn she had 30 other pen pals. Morag never appeared in the strip again after 1998.
An unproduced animated special called "Will Ye No Come Back Again, Charlie Brown?" was planned to continue her story. The script was adapted into the 2021 graphic novel "Scotland Bound, Charlie Brown" by Boom! Studios, written by Jason Cooper and Robert Pope. In that story, Charlie Brown travels to Scotland to meet Morag but misses her. He befriends a Scottish girl named Nell instead, who becomes his new pen pal.
Apple TV has produced new Peanuts specials annually since 2021. A 2027 special called "Snoopy Unleashed" will feature Charlie Brown's pen pal making her official animated debut. The character, named Mia, is a wheelchair-using Londoner of South Asian descent, voiced by Lara Mehmet. Her arrival triggers Snoopy to run away to the city, prompting the gang to chase after him. This marks the first time one of Charlie Brown's correspondents will appear on screen in official Peanuts media. The recent special "Welcome Home, Franklin" in 2024 also expanded Schulz's work by giving Franklin a center role.