Muggles' Guide to Harry Potter/Characters/The Fat Lady

Overview
The Fat Lady is the subject of a painting on the seventh floor of Hogwarts Castle. Her portrait guards the entrance to Gryffindor Tower. Students must tell her the password that she has created to enter the Gryffindor common room.

Philosopher's Stone
When Harry and the other first-year students arrive at the entrance to Gryffindor Tower, Percy addresses the portrait of a very fat lady, in a pink silk dress, to give her the password, "Caput Draconis." Never named, the portrait is called The Fat Lady throughout the rest of the series.

When Harry departs for his Wizard's Duel with Draco Malfoy, Ron accompanies him as his Second while Hermione tags along to try and persuade them to return to Gryffindor Tower. Unsuccessful, she tries to re-enter the common room, but is unable to get in because the portrait is now blank; the Fat Lady has gone visiting. When they run into Neville in the hall, Neville says he had forgotten the password, and the Fat Lady would not let him enter. As they return from the failed duel, the Fat Lady asks what the four of them have been doing, but simply opens the entrance when Harry gives the password.

When Harry, trying out his new Invisibility Cloak, leaves Gryffindor Tower the night after Christmas, the Fat Lady squawks, "Who's there?" as he exits. Harry does not reply.

Chamber of Secrets
When Harry and Ron first reach the Common Room after landing the flying car in the Whomping Willow, the Fat Lady asks them for the password; of course they do not have it, but Hermione tells them ("wattlebird"). The portrait swings open to reveal a large welcoming party in progress – apparently Harry and Ron are somehow heroes for having taken unconventional means to get to the school.

While Harry goes through the portrait hole a number of times in this book, even under the invisibility cloak, this is the only time that we see or hear him interact with the Fat Lady.

Prisoner of Azkaban
The Fat Lady refuses to let Sirius Black into Gryffindor tower at Hallowe'en because he does not have the password. He destroys her painting in a rage. She leaves the portrait out of fear for several months; during her absence, the entrance to Gryffindor Tower is guarded by Sir Cadogan.

When Sir Cadogan allows Sirius into the tower, he is sacked. The Fat Lady is convinced to return, but she requires that a squad of security trolls be provided to keep her safe.

Goblet of Fire
When Harry Potter and Ron Weasley were called by Hermione Granger to go to the kitchen, the Fat Lady was annoyed that she had to open the door just after they planned to not use it.

Later that year, after the Yule Ball ended, the Fat Lady and Violet, a witch from another portrait who was visiting her, were both drunk, and Harry Potter had some trouble getting her to open the door.

Once, when Harry tried to enter the tower, the Fat Lady was asleep, and he had to shout the password to wake her up, much to her irritation.

Order of the Phoenix
Harry is first to the Gryffindor dorm's entrance on his first night back at school, but he does not know the password, and the Fat Lady will not let him in. Neville, arriving almost on Harry's heels, says that he will be able to remember the password this year; it is Mimbulus Mimbletonia.

On the Thursday of the first week of classes, Harry, returning from detention with Professor Umbridge near midnight, runs into Ron in the hall. When they reach Gryffindor tower, deep in conversation, the Fat Lady is dozing; after a while, she testily asks them to give the password so she does not have to keep listening to their conversation all night.

Half-Blood Prince
When Harry returns from Christmas break, Hermione informs him that the new password is "Abstinence". Apparently the Fat Lady had somewhat overindulged over the break – there is mention of her visiting a picture of some happy monks with wine casks.

When Harry returns from retrieving a memory from Professor Slughorn, the Fat Lady denies him entrance to the Common Room. Nearly Headless Nick, passing by, stops to mention that Professor Dumbledore has returned and is in his office; Harry elects to report to Dumbledore immediately, instead of returning to his dormitory.

The Fat Lady is mentioned at the end of the book where she is told by Harry that Dumbledore is dead, she then wails in despair and swings forward to admit Harry into the common room without a password.

Deathly Hallows
While Harry does eventually head for Gryffindor Tower to get some sleep after the battle at Hogwarts, we leave him before he reaches the Fat Lady's portrait, and so we don't actually see her in this book. We hope that she will let Harry into the dormitories given his recent efforts on the school's behalf; there is mention that all the occupants of the portraits are wandering the school to monitor the battle, and that all the historical Headmasters in their portraits cheer Harry on his return to the Headmaster's office, so we can assume that the Fat Lady is at least as well aware of Harry's role in the battle.

Relationships with Other Characters
As early as the first book, we learn that at night the Fat Lady leaves her portrait and goes visiting.

In Harry Potter and the Goblet of Fire, a witch in a portrait in the small room where the Champions gather after they are selected hastens off as Harry is announced as the fourth Champion. We later see her sharing the frame with the Fat Lady; she has evidently told the Fat Lady of Harry's selection as fourth Champion. The same witch, identified as Violet or Vi, is later seen sharing a box of liqueur chocolates with the Fat Lady; they are both rather tipsy at that point.

In Harry Potter and the Half-Blood Prince, it is mentioned that the Fat Lady and Vi between them had drunk all the wine in a picture of monks over Christmas; as a result, the Fat Lady has chosen the word "Abstinence" as the new password.

Analysis
We note that all of the common rooms, not just Gryffindor, must have some way of barring the entrance to those not of that House. The Fat Lady is the only portrait charged with that job as far as we know. In Harry Potter and the Chamber of Secrets, we will see that the Slytherin common room is reached by providing the password to a particular stretch of blank wall; in Harry Potter and the Deathly Hallows we will see that entrance to the Ravenclaw common room is allowed in response to answering a philosophical question posed by a brass eagle's head. We never see the Hufflepuff common room. However, the Fat Lady seems to be part of a pattern of doorways hidden behind magically-animate objects; we learn later of the carved gargoyles guarding the headmaster's office, and the still life painting that allows access to the kitchens. Curiously, there are apparently two carved gargoyles guarding the entrance to the staff room, mentioned only in Harry Potter and the Order of the Phoenix, but not in any of the other books where Harry has business in the staff room.

The Fat Lady is a very minor character, and as she is a portrait, she can not change, at least not much. Whatever character traits we see in her will be, presumably, fixed as of the day her portrait was finished. That said, one must suppose that a portrait, whose job consists of being in one place all day in case someone needs entry to a place she is guarding, must get bored. This would explain her "going visiting", which we see occurring within the first month of Harry's first year; it likely would also explain her drinking, as there is a plethora of alcohol in the various paintings, and one assumes it cannot be permanently consumed. It is a little odd that a painting, which presumably does not have much of a metabolism, can suffer a hangover; however, our interactions with the Fat Lady lead us to believe that, painting or no, she does have the ability to form, act upon, and be changed to some extent by memories.

We also suspect that the Fat Lady's experiences with alcohol may be meant as something of a warning to readers. With the exception of Winky, and in later books Professor Trelawney, no characters - even if they do drink alcoholic beverages in large quantities, as Hagrid apparently does - are seen as having a drinking problem of any sort. In all three cases, but particularly with the Fat Lady, the bad aspects of alcohol, specifically confusion ("Lairy fights, that's right") and hangovers, are displayed in a way that might cause the young potential imbiber to re-think matters. It is to the author's credit that she manages to show the point without belabouring it.