When Francis Monogram was five years old, he had always wanted a pony for Christmas. The wish was never granted, and for this, Major Monogram possesses a lasting disdain towards Santa Claus. ("I, Brobot") He also had a dream of becoming an acrobat, however he was forced to follow in his father's footsteps and trained to fight evil.
At a young age, he was forced to move off to a place known only as "The Academy" along with actor Ray Liotta, which he now looks back at as a painful memory. It had been forced upon him by his supposed father, who also attended the Academy. ("Minor Monogram") As desperately as he'd tried to negotiate his father out of the decision, his father declined, saying that the matter was permanently settled and that he wasn't Francis's father. ("Get That Bigfoot Outa My Face!")
As an adult, he was employed into the O.W.C.A. where he worked his way to becoming a superior officer.
Major Monogram currently holds the title Major and is head of his branch of the O.W.C.A., a secret, all-animal organization that fights crime and evil. He transmits messages to Perry the Platypus (and most likely to other agents as well) as Carl, his scrawny redheaded intern, films them.
An interesting quirk he has is that he sometimes doesn't wear pants as he debriefs Perry the Platypus, though he does when he is on the field or in public. ("I Scream, You Scream", "Unfair Science Fair Redux (Another Story)") This appears to be because of the importance of professionalism and general avoidance of potentially embarrassing situations.
When he transmits messages to Agent P, he is wearing a wig. He is bald as a result of their new pneumatic transporter. ("Unfair Science Fair", "Perry Lays an Egg") His mustache is also fake; he was seen trying out different fake mustache styles. ("I Was a Middle Aged Robot") He also has a unibrow, which has resulted in Heinz Doofenshmirtz nicknaming him "Major Monobrow". ("Spa Day", "Phineas and Ferb Summer Belongs to You!")
Recently, his old age has been getting to him. A great example can be the simple fact of his back failing, causing him to be unable to brief Agent P for the day. His intern, Carl, had to do it for him. ("The Flying Fishmonger")
Major Monogram has mentioned having gold teeth, a copper spleen, and being 35% metal. ("Phineas and Ferb Summer Belongs to You!")
In later life, Major Monogram eventually retired from the OWCA and went to a "better place", specifically Bora Bora. His intern, Carl, was promoted to commander. The two remained in touch and remain friendly over the last decade. He grew out his previously short hair to down his neck, grew a small beard that goes to just below his chin, and wore a blue and pink Hawaiian shirt. ("Act Your Age")
In an altered reality involving time travel gone awry, Dr. Doofenshmirtz took over the Tri-State Area and Major Monogram was forced to sign an oath with Doofenshmirtz. He looks very old, with a long white beard. His unibrow is still gray, and he still has his mustache. He still has his job, but Agent P has been failing a large number of missions ever since the beginning of summer, when he got hit by a giant piece of tin-foil, resulting in him having to stay in a whole body binding for 18 months, which is when Doofenshmirtz got the "upper hand," which resulted in his taking over the Tri-State Area. Once since they signed the oath with Dr. Doofenshmirtz, it seems all missions were failures. ("Phineas and Ferb's Quantum Boogaloo")
He has a serious personality and he acts as he is in his O.W.C.A. possition, all the time, even when he worked in the Slushy Burger ("Phineas and Ferb Save Summer") and when he send his card to Santa Claus , He acted as a Major. Despite of this, Francis can make jokes if he tries. In several episodes, he has shown little patience for events such as Carl's awkwardness or Doofenshmirtz's nonsense.
In various episodes (i.e. "Where's Perry? (Part Two)"), he has been shown to care much for the money that is spent in the O.W.C.A.
Easily motivable and irascible, he has been shown to motivate excessively with positive events (such as his birthday in "Backyard Hodge Podge" or the fight between Perry and Doofenshmirtz in "Misperceived Monotreme"), and, on the other hand, acting drastically to negative events (such as when people calls for his name in "Phineas and Ferb Musical Cliptastic Countdown" or when he thought all was lost in "Where's Perry? (Part Two)").
He was proved as unable to do anything by himself and incompetent to new technologies ("A Phineas and Ferb Family Christmas", "Remains of the Platypus", "Candace Disconnected") and not caring too much about the recommendations of the others ("Remains of the Platypus").
In Split Personality is revealed that he has a side that wants to sing but he keeps it underwraps.
Francis has fair skin, white hair in a buzz-cut, a grey monobrow, and a bushy white mustache. His hairline is a widow's peak. He has a big nose with both eyes lying on one side or it, as pointed out by Carl. ("That's the Spirit") Because of this, he has to wear special sunglasses designed by family friend, M.C. Escher. ("Where's Perry?" (Part Two))
His regular uniform consists of a green long-sleeved shirt and pants. The shirt has a dark grey collar and dark grey lines down the shoulders and front and around the cuffs. His initials "MM" are monogrammed in purple on the right breast of the shirt. The pants have dark grey lines down the sides of the pant legs. He wears black shoes.