[10] At age 14, he regularly sold gag cartoons to Child's Life, Flying Aces, and Inside Detective magazines.

[3] When he was 15, he drew a comic strip, The Lime Juicers, for the weekly Kansas City Journal, and worked as a staff artist at the same time for an industrial publisher.

Walker's physical presence in Columbia is noted by The Shack, which was a rambling burger joint behind Jesse Hall on Conley Avenue.

The Shack was destroyed in a fire in 1988 and Walker returned in 2010 for dedication of a replica of the building in the student center with the dining area now formally called "Mort's".

[12][14] A life-sized bronze statue of Beetle Bailey stands in front of the alumni center which is near The Shack's original location.

[15] In 1943, Walker was drafted into the United States Army and served in Italy, where he was an intelligence and investigating officer and was also in charge of an Allied camp for 10,000 German POWs.

[16] Walker graduated in 1948 from the University of Missouri, where he was the editor and art director of the college's humor magazine, Showme, and was president of the local Kappa Sigma chapter.

[17] When he decided he could make more money doing a multi-panel comic strip, Spider morphed into Beetle Bailey, eventually distributed by King Features Syndicate to 1,800 newspapers in more than 50 countries for a combined readership of 200 million daily.

[3] In his book The Lexicon of Comicana (1980), written as a satirical look at the devices cartoonists use, Walker popularized[a] a vocabulary called Symbolia,[17] including the term "squeans" to describe the starbusts and little circles that appear around a cartoon's head to indicate intoxication,[10] and grawlixes to indicate the typographical symbols that stand for profanities, which appear in dialogue balloons in the place of actual dialogue.

[26] In 1978, Walker received the American Legion's Fourth Estate Award, and in 2000, he was given the Decoration for Distinguished Civilian Service by the United States Army.

[28] Walker received the Sparky Award for lifetime achievement from the Cartoon Art Museum at the 2010 New York Comic Con.