The name "Lila" first appears in the strip from February 17, 1968 in which Charlie Brown points out to Snoopy that, although he received valentines from many different girls, he did not get one from Lila. Snoopy briefly becomes upset, believing that Lila does not love him anymore. The character would be referred to again in a series of comic strips which ran between June 3 and June 8, 1968. At the beginning of the series of strips, Snoopy receives a letter from Lila in which she says that she is coming to visit. Snoopy cannot bear the emotional pain of seeing Lila again and hides in his doghouse until she has gone.
The character made her first (and only) appearance in the strip on August 24, 1968, as part of a series of strips which originally ran between August 20 and August 31 of that year. The storyline begins with Snoopy receiving another letter from Lila, which he is at first reluctant even to open. When Snoopy finally opens the letter, he discovers that Lila is in the hospital and goes to see her. Charlie Brown, who has no idea who Lila is, finds Snoopy's behavior very confusing. Linus tells his friend that he has done some research and has found out who the girl is. In the strip from August 30, 1968, Linus reveals that Lila was Snoopy's original owner, having bought the young beagle at the Daisy Hill Puppy Farm. Lila loved Snoopy very much but her family, who lived in an apartment building, decided that they could not keep him. Snoopy was returned to the Daisy Hill Puppy Farm and was subsequently bought by Charlie Brown.
The character was voiced by Johanna Baer in 1972 and Megan Parlen in 1991.
- Lila is one of the many Peanut characters to appear in the video game Snoopy's Street Fair, in which, she owns a chocolate booth.