The character is only slightly different in all versions; in the original novel, Burns was a borderline incompetent and egotistical doctor who blamed others for his own shortcomings; in the film, he is also a brooding religious fanatic, while in the television series he is an officious, frenetic, pompous twit obsessed with military order.
In the original novel, Captain Burns is described as a well-off doctor who had attended medical school but had no true formal training as a surgeon other than a long apprenticeship with his father in Indiana. He comes off as being, therefore, dismissive of those (such as the Swampmen) who actually went through a residency for their training. However, this masks serious shortcomings in his surgical style, which he dismisses as failures of others further in the process. Duke Forrest remarks that when one of Burns' patients dies, "It's either God's will or somebody else's fault." This practice comes to a head when he accuses Private Boone of killing a patient of his, through improper administration of medicine and generally berates him. After a while, both Hawkeye and Trapper assault Frank, in separate incidents. It is this turmoil that causes Blake to nominate Trapper as Chief Surgeon.
Later, after Burns and Houlihan commence a sexual affair, the Swampmen latch onto it, and one day at mess, Hawkeye makes some ribald comments about the relationship. Burns, having reached the limit of his patience, violently assaults Hawkeye. The next day, he is sent away for psychiatric evaluation, leading Duke to remark: "If I nail Hot Lips and punch out Hawk, can I go home, too?"
When the new head nurse, Major Margaret "Hot Lips" Houlihan arrives, the pair soon fall for each other. In the film version (unlike the novel) it is only Henry Blake who calls her O'Houlihan. All of the other characters refer to her as "Major Houlihan". This was a mistake on the actor's (Roger Bowen as Lt. Col. Henry Blake) part. But Altman decided to leave this in the film to further show just how befuddled Blake really was. When the two meet in Houlihan's tent to dictate a letter condemning Hawkeye, Trapper, and Duke, they soon begin having sex. What neither of them know is that a microphone has been planted underneath Houlihan's bed by Radar (Corporal O'Reilly). Every sound the pair make during sex is heard in the clerk's office (including Houlihan's insistence that Burns kiss her "hot lips", resulting in her legendary nickname). Soon Trapper decides that this has to be shared with the rest of the camp, and he puts Burns and Houlihan on the PA.
The next morning, Burns gets into a fight with Hawkeye when the latter asks Burns how Houlihan was in bed, demonstrating noises. As a result, Burns attacks Hawkeye physically (with Trapper adding fuel to the fire by warning Hawkeye to watch his privates because Burns is a sex maniac), and is sent to a psychiatric hospital in a straitjacket. This is the last the audience sees of him in the movie.
It should be noted that the film's Major Burns was a combination of two characters from the novel—-the small-minded twit Captain Burns (who had a liaison with Major Houlihan, as in the film, but did not live in The Swamp [he was moved out a week after Hawkeye and Duke arrived after they complained to Henry Blake]) and the religious fanatic Major Hobson (whom Hawkeye and Duke had ousted from The Swamp because of his obsessive praying).
While the TV Burns would appeal occasionally to religious and moral values (typically in the process of showing himself up), the emphasis in story lines was more on his surgical and personality shortcomings, than on his sanctimony. Burns' unpopularity with most of the show's other characters can be ascertained by his nickname, "Ferret Face" (which was originally given to him by his brother, as revealed in episode 1.18). When he failed to get his own way, or one of his schemes to discredit Hawkeye would fail, he would go off somewhere and sulk, or would throw a temper tantrum.
In 5.22, Frank is shown to have bought a Korean National Art Treasure (a priceless 800-year-old vase) on the Black Market, which he attempted to smuggle to his wife in Fort Wayne; but Hawkeye and B.J. put a stop to that, by replacing the vase with a worthless bedpan. Despite the fact that he detests enlisted men, several episodes seem to point to Burns as having elements of trust in, if not concern for, Radar. He is also quite simple-minded: when Trapper's friend (2.24), an Army Intelligence officer, is working undercover as an engineering officer, Frank very willingly accepts the man's far-fetched story that the US Army Corps of Engineers is attempting to make MASH hospitals amphibious.
In 4.21, he refuses to believe the fact that Sergeant Zale lost money gambling ($300 to Radar), on the grounds that gambling has been prohibited (refusing to consider it could go on behind his back), so he concludes that the "missing" money must have been stolen. Even at home he is a klutz; while serving as a Scoutmaster, he accidentally set fire to himself.
While portraited as being completely unbearable in the series, on some occasions Burns showed signs of humanity. He was very sensitive to his Swampmates' defeated comments about "being a friend once" after he declined doing something. Also, after Pierce and McIntyre foiled one of his schemes, after being offered a coffee, he asks the two why he can't get mad on them. In one episode ("Germ Warfare), he was forced to rest in post-op because of anemya, after McIntyre and Pierce soaked some blood from him in his sleep to save a patient. Frank played checkers with that patient, and also was flattered after Hawkeye and Trapper gave him flowers (although he threw them away after being insulted). Perhaps the two most visible attempts of becoming a human being undertook by Frank were associated with Hot Lips. In one episode, when Margaret was absent in Tokyo, Col. Potter asked Pierce and B.J. to ease up on Burns and to make friends with him, as it was impossible to live with him for a while. They invited him to a poker game, in which Frank got drunk on all their moonshine and won a lot of money without having any practice in the game before. After the game, he called his Swampmates friends in the bar and hugged them, also asking an obese nurse for a dance, though he was still extremely drunk. The attempt of making friends with Burns eventually was foiled. After sobering up, Frank was nice to his mates in the morning, but B.J. and Hawkeye were too angry with Burns - they played a drunken prank on him and the next day, they had to drive to an attacked medical outpost, as a completely drunk Frank fell into an ambulance and with driven there, the driver being unaware of his passenger.
In the second episode of the fifth season, Houlihan returned from Seoul engaged to Donald Penobscot. Frank's behavior was very erratic, and Margaret unwittingly fueled it up. It was also one of the moments in the show where Hawkeye was sorry for Burns, as he felt disgusted with Margaret's talking about Penobscot in Frank's presence; while it was the period when Pierce started getting on good terms with Hot Lips, he still felt that Frank has the right to be malicious to her. In the final scene, Burns played a verbal joke on Houlihan in the cantine, which left her visibly shocked. B.J. admitted it was a clear shot and moments later, the three had a big laugh, which appeared to be sincere.
Burns' bungling in surgery has led to more than one headache, it is suggested that only the intervention of other doctors has averted the death of his patients in some instances. His inefficient surgical skills are a constant source of humor throughout the series, even after he left.
Burns' incompetence is also readily apparent to the enlisted men. In an episode where Hawkeye and Trapper arrange for an illegal nose-job for a depressed soldier, they stage an injury to Radar to justify the presence of a plastic surgeon in the camp. Hours later, Burns sees Radar without bandages on his nose, and asks how a broken nose could have healed so quickly. Radar quickly says that it was only sprained and so he was advised to stay off it for a few days. Burns responds: "I'm a doctor, and that's crazy!" to which Radar responds "I've heard that, Sir."
Even the Korean doctors (North and South alike) are aware of Burns's ineptitude. In one such case, Burns is kidnapped by two North Koreans in disguise who plan to use him as a cover to get through a series of checkpoints. However, fed up with their captive's apparent incompetence, they order him out of the jeep as soon as they pass through, telling him, "Go back to your unit. It's the best thing you can do for OUR side!"
During an inquiry (in "Novacaine Mutiny"), Burns quizzes a military lawyer about his service record, and is told, "If you hadn't been drafted as a doctor, you'd probably have been assigned as a pastry chef." (Yet Frank's culinary talents are also suspect; he once was injured in his eye during a sniper attack while trying to crack an egg, an episode he passed off as an injury from "shell fragments" when putting in for a Purple Heart.)
Burns, along with Houlihan, often tried to undermine Commanding Officer Lt. Col Henry Blake due to Blake's rather lax approach to those under his command and in his desire to take control himself. Several times he goes over Blake's head to complain about events at the camp; one example of this is when Pierce was appointed Chief Surgeon over him; he then appealed directly to General Barker (Sorrell Booke). Initially ready to send Hawkeye packing, Barker winds up so thoroughly impressed with him that he tells Henry to give Burns a high colonic and send him on a ten-mile hike with a full pack as punishment for wasting his time. Henry once threatened to note in Frank's personnel file that Frank did not work and play well with others. Frank spent most of his time on the series battling and antagonizing virtually everyone in the camp, specifically his tent mates and commanding officers. By the fifth season, he was the show's main antagonist (having lost Houlihan as an ally upon her engagement) and, essentially, the closest thing the series had to an actual villain, aside from the North Koreans; a fact commented on by B.J. upon hearing of his removal ("This reduces the enemy to just North Korea!").
On the few occasions when Burns commanded the camp, he would frequently lord his own authority over others by micromanaging camp operations, just for the sake of being in command. For example:
Burns also seems to not know Army regulations as well as he says he does. In Officer Of The Day, when Col. Flagg brought a prisoner to be treated so he could execute him later, and Hawkeye and Trapper refuse to release him, Frank ordered them to release him, which is against Army regulations. However, he may well have ignored the regulations in order to curry favor with Flagg. This would not be first time that Burns has gone against Army regulations in order to gain favor of a superior officer. In Officers Only, when Hawkeye informed General Mitchell that his son could not enter the newly built Officers Club because his son was a private, Burns (as well as Houlihan) stated that General Mitchell's son should be allowed to enter the club, although that would be against Army regulations. Despite his bullying and gung-ho patriotism, in several episodes, Burns shows himself to be a panicky coward in crisis situations. One trademark feature of Burns is that when he is drunk, happy, or asleep, he lets out an irritating, high screech of a laugh.
When Blake left, and died on his way home, Burns (who actually wept when he heard of Blake's death, one of the few times he ever showed any genuine humanity) was initially slated to take command of the camp. However, the Army soon appointed a new Commanding Officer, Colonel Sherman T. Potter. Burns was so upset that he ran away to sulk and returned several days later. Everyone except Burns liked the new commander from the start, even Major Houlihan. Burns, having never gotten over being passed for commander, made it a point not to get along with Potter, often making insulting comments regarding Potter's age, (one time, Burns called Potter an old dimwit, while he was screaming at Radar). Potter in turn referred to Burns as the camp's "head twerp". During various episodes, Burns is almost always filing charges against nearly anyone and everyone who dares to go against him or even mildly disagree with him, most especially Hawkeye Pierce, whom he clearly despises. With Potter's arrival, Frank now had more formidible opposition (backed up by the likes of Hawkeye, B.J., Radar, Klinger, Mulcahy, and eventually Houlihan herself). In the episode, "Ping Pong", he vows to put a stop to the antics of a wedding between a Korean Ping-Pong player and his fiancee, but Margaret puts him in his place. Even during the wedding, Burns, who is the only officer not dressed in his formal Military uniform, vowed that the camp wouldn't get away with this wedding and that he would go to a General Harrelson about it, but Margaret, also involved with the wedding (and someone who used to back him on such matters), forcefully tells him to shut up.
After Margaret and Donald left on their honeymoon, Frank was left alone and heartbroken, finally realizing he would never get Margaret back. During their honeymoon, Burns was sent on leave to Seoul. While there, he suffered a breakdown and started running wild throughout the city with the Military Police in pursuit until he accosted a General's wife (whom he mistakenly thought was Houlihan) in a public bath. As a result of a psychiatric examination after his capture, he was sent back to the States. Potter, Radar, Pierce and B.J. have one last toast in Frank's honor. Hawkeye's last words on the matter are: "Goodbye, Ferret Face!" However, Burns has the proverbial "last laugh": to Hawkeye and B.J.'s disgust, and which caused Hawkeye to throw the portable phone out the door in a savage fury, he is promoted to Lieutenant Colonel with all the charges against him being dropped, and posted to a VA Hospital in Indiana. (Hawkeye sarcastically referred to this as a decision made by "the army in its infinite wisdom", and what was worse, was that he was cleared of all charges of accosting the General and his wife.) Burns was replaced with Major C.E. Winchester III, who by contrast, was considered an excellent surgeon even by the people who disliked him. Winchester also had a relatively more bearable personality and unlike Burns, Winchester actually has compassion for others.
Burns was written out of the series at the request of Linville. Linville (who once commented that there was actually a very dark aura hovering over Frank, that Frank was not all that stable, yet still operating on patients) felt that the character of Frank Burns had gone as far as it possibly could, with the way the series had developed. Burns' leaving is generally seen as the last straw in the "funny" years of the show, with latter storylines mainly focusing on the horrors of war.
At least twice Burns tried to claim a Purple Heart for minor injuries he incurred at the camp, but quick work by Hawkeye and either Trapper or B.J. made sure Frank could never keep the spurious award, One medal (for throwing his back out dancing with Major Houlihan) goes to a wounded GI (1.17), and the other medal (for an eggshell fragment in his eye from breaking open a hard-boiled egg and Frank claimed it was a sniper shot) is awarded to a just-delivered wounded baby (4.9) (However he keeps the medal upper ribbon). In 5.14, he even tried to steal one from an unconscious patient, but Hawkeye and BJ walked in, forcing him to abandon the attempted-theft.
[To Radar] "Don't give me any of your snottiness, I am not that old dimwit [referring to Colonel Potter] you work for!"
"Well I wouldn't kill just anyone, Margaret."
"Nobody double dares me and gets away with it!"
"Oh, pish posh."
[During a Korean wedding] "They won't get away with this! General Harrellson will hear about this!"[Margaret replies, "Oh, shut up!"]
"Oh, go peddle your fish!"
"Oh, go peddle your petunias!"
"Oh, go practice your putts!"
[To Margaret, during a temper tantrum he is throwing after learning that Pierce and not he, will perform Margaret's appendectomy] "I should be doing this operation! I know Major Houlihan's appendix better than any of you! [...] I hope you get a great big scar!"
"We all know it's brutal up there at the front, especially those of us at the rear."
"I'm sick of hearing about the wounded. What about all the thousands of wonderful guys who are fighting this war without any of the credit or the glory that always goes to those lucky few who just happen to get shot."
"Margaret, I get so excited when you say the word excited."
"We're so lucky to be two of the few and not the many."
[after Hawkeye apologized for putting peanut butter in Frank's stethoscope] "And autographing my mother's picture: Dear Frank, Dad was not your father. Love Mom?!"
[During assembly] "I hope you realize that by trying to introduce more discipline, more order, I've hopefully made this a more enjoyable war for all of us."
[During the Army Life song] "Oh Hawkeye and oh BJ, they think they're pretty smart. I'd love to take a scapel and stab them in the heart!"
"I can't wait two days! That'll be...three days ago!"
[When told by Hawkeye that he made up a phony stock to make Frank look foolish] "I don't need your help!"
"If I close my eyes my brain won't get any air."
[Hawkeye: "Hi, Frank.", Trapper: "Hello, Frank."] "That'll be the day."
[Watching Margaret fly away on her honeymoon] "Good-bye, Margaret."
[Trying to insult Hawkeye] "Stink Fish-pot"
"Unless we each conform...unless we obey orders...unless we follow our leaders blindly - there is no possible way we can remain free."
"That's the last tray you're going to upset, soldier, there's a war on! And we've no time for violence."
"Oh, stop dreaming and go to sleep!"