He was a World War II veteran who had his shins "blowed off by a Japanman's machine gun" in combat and later had his feet attached to his knees as a result.

Cotton was zealously proud of his military service record and his status as a war hero, although he tended to exaggerate his exploits.

In the 12th episode of season 11, he is wearing the third class of the Legion of Honor, the highest award given by the French government, who gave it to a select handful of American troops for their service in World War II.

For example, in the episode "Cotton's Plot" he stated he killed Nazis ("Nazzys") in Munich on April 30 and Japanese ("Tojos") on May 2 in Okinawa.

He also has expressed dislike for veterans of the Vietnam War, as he blames them to some degree for losing it - though he eventually accords them a measure of respect for trying their best.

Thanks for trying, soldier... As commanding officer of the local VFW post, I would be honored to have you fellas join our organization...Aside from some confirmation from his war buddies, it is unknown if Cotton actually ever served in Europe, considering the 77th served in the Pacific Theater and the majority of his war flashbacks are shown to take place in the Pacific fighting the Japanese.

His unit was pinned down by a Japanese machine gun nest high up in a hill, so he sneaked into a fifty-five gallon barrel of sake.

By September, he was skinny enough to slip through the bars, and strangled the guard with a string made of braided rat tails, and ran to safety.

("Returning Japanese") Miscellaneous: Cotton severed the windpipe of a German corporal with a two-foot strand of dental floss he kept in his boot.

Climbing onto a grill table, he chokes on a piece of shrimp (to which he is extremely allergic), then slips and falls on the hot surface.

He is taken to the hospital and diagnosed with a hip fracture, severe burns on his arms, torn ligaments in his ankle/knee joints, and an infection of his esophagus due to swallowing the shrimp.

In spite of his injuries and a heart attack suffered while in the hospital, Cotton survives long enough to torment both Hank and Peggy, even slowing his heartbeat down to feign death (a trick he learned while confined to a Japanese POW camp).

In the final scene of the episode, Dale Gribble fulfills a request from Cotton to blow up a storage shed Hank has built.

He was to have been buried at the Texas State Cemetery, a grave which he earned in recognition of his military service, as explained by the episode "Cotton's Plot", although he ended up being cremated instead.

In the season 13 episode "Serves Me Right for Giving General George S. Patton the Bathroom Key," Hank receives from Didi a box containing Cotton's personal possessions and a list of embarrassing last requests.

Hill suffered from several injuries ranging from four rusty bullets lodged in his back (one in his heart) from his military service, a broken hip and torn ligaments in his ankle-knees, to an infection in his esophagus and severe burns caused by a freak shrimp accident that occurred earlier this week at Tokyaki's Japanese restaurant.

He talks down to women, berates his son, is prone to violent outbursts, and on more than one occasion has exhibited homicidal tendencies.

He even attempts to pass on some of his sexist traits to Bobby at one point, teaching him that women should be made to cook and clean for their husbands all day long.

On rare occasions, Cotton shows a vulnerable side that he normally keeps hidden: he realizes that he was a terrible father and person, hates himself for growing old and becoming disabled, and readily admits that he would die to protect his grandson, Bobby ("Revenge of the Lutefisk").

He also appears to not be bigoted towards black people or Jews, as he is shown interacting with both groups and acting more well-mannered than he usually is (when he finds out his ex-wife's new boyfriend Gary is Jewish, he wishes him a Happy Hanukkah and says that one of his war buddies was also Jewish; presumably this is the "Brooklyn" man Cotton mentioned as having sacrificed himself during a shark attack so Cotton and others could escape alive, albeit horribly injured).

Through tough love and intense physical therapy, Cotton also helped Peggy walk again after a debilitating skydiving accident crippled her.

Hank was initially wary of this, because he feared that Cotton was simply taking advantage of Peggy's brief disability in order to humiliate her.

Before leaving Japan, Cotton had an affair with a Japanese nurse, Michiko, which resulted in the birth of his eldest son (and Hank's older half-brother), Junichiro (voiced by David Carradine); he left suddenly despite trying to stay, and knew nothing of his child until years later (a flashback clip shows him being clubbed and dragged onto the troopship leaving Japan).

After the war, Cotton supervised the installation of asbestos in eleven bowling alleys and every public school in Heimlich County.

Cotton eventually traveled back to Japan to reconcile with his long-lost lover, and soon learned of his illegitimate son.

Junichiro initially rejected Cotton's attempt to make peace, and formally renounced his Hill family heritage.

This enraged Cotton, who re-declared war on Japan and planned to spit in the face of Emperor Akihito out of spite.

In spite of all this, however, Cotton never hesitated to refer to Hank as "My Boy," and on several occasions tried to help him (such as when Kahn and Minh were befouling his house).

Throughout the series, Cotton has also shown several times that he may actually care for Hank, such as calling him a good son in "Returning Japanese", saving him from being shot in the episode "Yankee Hankee", and leaving and trusting Hank with his last requests and personal possessions in "Serving Me Right for giving George S. Patton the Bathroom Key".