The A-Team is a group of ex-United States Army Special Forces who were wrongly convicted of a crime during the Vietnam War. They fled to Los Angeles, where, as fugitives, the A-Team work as soldiers of fortune, using their military training to fight oppression or injustice. Murdock, along with Hannibal Smith, B. A. Baracus, and Templeton "Faceman" Peck make up the A-Team. Although Murdock was not convicted of any crime, as the other three were, he is still a full-fledged member of the team.
Considered the best chopper pilot of the Vietnam War, Murdock is officially declared insane (possibly caused by post-traumatic stress disorder) when the other three are imprisoned for robbing the Bank of Hanoi. Although he was alleged to be the A-Team's pilot during the robbery, he is instead committed to a psychiatric hospital. It is sometimes unclear if Murdock is truly insane or only exceptionally good at pretending he is (or a combination of the two). He is stated as having paranoid delusions and intermittent memory loss. It is suggested one has to be insane just to do the stunts he does in his helicopter.
Murdock is committed to a Veterans Administration (VA) Psychiatric Hospital, although he routinely escapes (generally with the help of Face) to accompany the A-Team on their missions. The symptoms of his "insanity" vary from episode to episode, but include self-identification with fictional characters, hallucinations, and belief in the "intelligence" of inanimate objects, among others. He is the most childish of the A-Team as shown that he often plays video games in his room and likes watching cartoons like Woody Woodpecker or Looney Tunes and sometimes will even repeat a Looney Tunes' character's catchphrase like Porky Pig's "th-th-th-that's all folks". He often "channels" a certain character for the duration of a mission (much to the chagrin of B.A.) or becomes fixated on a particular subject to the point of obsession. He also frequently refers to his invisible dog, "Billy". B.A., uneasy with Murdock's unusual behavior, is easily annoyed by Murdock and regularly refers to him as a "crazy fool".
Murdock is almost always seen in a ball cap, a customized A-2 leather flight jacket with a picture of a tiger and the words "Da Nang 1970" on the back, a pair of khaki pants, and a pair of black Converse sneakers. He also often wears a t-shirt with a comical caption or a picture of cartoon characters like The Jetsons on it. Schultz said in a later interview that he was the one who devised the captions on the shirts, saying it was his "one constant contribution to the show." Although he was a helicopter pilot in Vietnam, he is easily capable of flying anything with rotors or wings, including passenger planes, fighter jets, and even autogyros. It is mentioned in the pilot episode that Murdock flew with the elite United States Air Force Thunderbirds (by the mental institution's doctor to Col. Lynch just before he questions Murdock about the A-Team). In the episode "Bounty" (Season 3), it is revealed that Murdock served two tours in Vietnam, has three unit citations and a Silver Star, and was wounded twice. Interestingly, unlike B.A., the initials H.M. were never explained in terms of what Murdock's actual first and middle name were, and the nickname "Howlin' Mad" were simply attributed to them (although it is rumored that his name comes from World War II Marine Corps General Holland M. Smith, aka "Howlin' Mad", a nickname given by his troops). Not even his driver's license reveals what "H.M" stands for.
It was revealed in the first season that Murdock and B.A. share the same blood type—AB negative, the rarest type. In the episode "Black Day at Bad Rock", B.A. receives a transfusion from Murdock, who was sprung from the hospital for just that, despite B.A.'s protests (fearing that Murdock's blood will make him "crazy"). This was again referenced in the second season finale "Curtain Call" when Murdock is shot and B.A. wants to donate his own blood to save him. This episode also has several touching moments between the two, as B.A. spends most of the episode caring for and comforting Murdock and showing that, for all their bickering, he and Murdock are actually very good friends.
Due to his nature, many of the details of Murdock's life are unknown, or possibly embellished. According to Amy in the pilot episode, Murdock's mother died when he was five (although they "still keep in touch"). If he is to be believed, he was raised (or at least influenced) by his grandmother (who is supposedly named "H. Emma Murdock") and his grandfather. In one episode in the third season, B.A. says that Murdock went insane after his plane crashed. The exact state of his insanity is never made clear, though he occasionally implies that his insanity is his ticket to his "room and board". Despite his purported mental status, Murdock is a thoroughly competent member of the team when needed to be. Indeed, because he is not actually wanted by the military, Murdock is often the only team member to evade capture by a given episode's antagonists (or the military police), and he has single-handedly rescued the other team members several times. On the other hand, his visibility and location as a mental patient make Murdock an easy target, and he is kidnapped twice from the hospital. The first time, in the episode "Bounty", Murdock was taken by bounty hunters who wanted to capture the rest of the team. In the episode "Wheel of Fortune" Murdock was drugged and taken by thieves who wanted to use his expertise as a pilot to hit an armored car with a Russian helicopter.
Murdock has extensive knowledge of various subjects and keeps up on current events, showing a genius-level aptitude. He speaks several languages including Spanish, German, Vietnamese, Japanese, Russian (not too well though) and Mandarin Chinese. In the second season episode "The Maltese Cow", Murdock says, "What can I say? One day I had a gonzo headache and before it went away I could read and speak Chinese. And it was a bad afternoon, too, lemme tell you." He also seems capable of a photographic memory. He is also a talented actor and often accompanies Face on his scams. He is capable of impersonating the voices of famous individuals and mimicking many different foreign accents. It is also revealed in the Season 4 episode "Wheel of Fortune", that Murdock has worked for the Central Intelligence Agency (CIA) on at least two occasions, once in 1969 and once in 1972. Details of Murdock's missions with the CIA are not revealed.
Murdock, as a Captain, has the second highest military rank in the team. In the team, nevertheless, Face looks to be the second-in-command, but in the 4th episode of the second season ("Bad Time on the Border") where Hannibal Smith is taken prisoner, it is Murdock who makes the plan for the rescue and the rest of the team follow him as leader. In the episode "The Road to Hope", the rest of the team is captured by a cell of domestic terrorists and Murdock organizes a group of homeless veterans to rescue them.
One particular insight into Murdock's unique world view comes during the season five episode "Trial By Fire". Murdock is asked to take the stand at the A-Team's murder trial and give testimony about his helicopter flight following the Hanoi bank mission. The testimony takes the form of a surreal flashback from Murdock's perspective in which Murdock himself (wearing a grey wig and Biggles-style flight jacket) and his female co-pilot come under attack from The Spanish Armada, a sea serpent, and a tribe of Native Americans mounted on horseback, while Murdock spouts melodramatic dialogue. His mental acumen, however had generally improved by the fifth season to the point that he agonized whether to tell team member Face that their current client A.J. Bancroft was in fact Face's real father, and that Bancroft's daughter was his half-sister.
Murdock was permanently discharged from the mental institution in the fifth season, supposedly having regained his sanity, which is consistent with the fact he possibly pretended to be insane as a cover. Following this event, instead of a different mental fixation every episode, Murdock took a different menial job each week, including stints working as a dog walker and a waiter.