Beetle was originally a college student named Spider at Rockview University. The characters in that early strip were modeled after Walker's fraternity brothers at the University of Missouri. During the strip's first year, Beetle quit school and enlisted in the U.S. Army on 13 March 1951, where he has remained ever since.
Most of the humor in Beetle Bailey revolves around the inept characters stationed at Camp Swampy, (inspired by Camp Crowder, where Walker had once been stationed while in the Army). Private Bailey is a lazy sort who usually naps and avoids work, and thus is often the subject of verbal and physical chastising from his supervisor, Sergeant Snorkel. The characters never seem to see combat themselves, with the exception of mock battles and combat drills. In fact, they seem to be in their own version of stereotypical comic strip purgatory (initially basic training, they now appear to be stuck in time in a regular infantry division). The uniforms of Beetle Bailey are still the uniforms of the 1950s to early 1970s Army, with green fatigues and baseball caps as the basic uniform, and the open jeep as the basic military vehicle. Sergeant First Class Snorkel wears a green Class A Army dress uniform with heavily wrinkled garrison cap; the officers wear M1 helmet liners painted with their insignia. While Beetle Bailey's unit is Company A, one running gag is that the characters are variously seen in different branches of the Army, such as artillery, armor, infantry, and paratroops.
Beetle is always seen with a hat or helmet covering his forehead and eyes. Even on leave, his "civvies" include a pork pie hat worn in the same style. He can only be seen without it once—in the original strip when he was still a college student. The strip was pulled and never ran in any newspaper. It has only been printed in various books on the strip's history. One daily strip had Sarge scare Beetle's hat off, but Beetle was wearing sunglasses.
One running gag has Sergeant Snorkel hanging helplessly to a small tree branch after having fallen off a cliff. While he is never shown falling off, or even walking close to the edge of a cliff, he always seems to hold on to that same branch, yelling for help.