-- George Weasley to the Fat Lady (GF12)
A painting of a large woman in a pink silk dress hangs over the round doorway into the Gryffindor Common Room. To gain admittance to through the portrait hole, a person must give the correct password to the Fat Lady, in which case she swings her frame out from the wall. She has been known to get a bit testy with people who wake her up for no good reason and even to wander off late at night out of her frame to go visiting, making it impossible to get into Gryffindor Tower. She is friends with Violet (GF17). At Christmas, The Fat Lady and Violet tend to consume a good bit of holiday cheer; during Harry’s fourth year they got a bit tipsy on chocolate liqueurs (GF23), and over the holidays of Harry’s sixth year they drank their way through quite a lot of five-hundred-year-old wine (HBP17).
In Harry’s third year, Sirius Black broke into Hogwarts and viciously attacked the Fat Lady’s portrait, ripping the canvas to shreds, making her flee her frame (PA8). She was found “hiding in a Map of Argyllshire on the second floor” (PA9). While she recovered, a painting of Sir Cadogan and his gray pony guarded the Gryffindor Common Room. When the Fat Lady was restored, she resumed her place but asked for added protection by security trolls (PA14).
When Dumbledore died, she allowed Harry into the common room without requiring a password, but wailed when he told her it was true (HBP29).
Passwords used to enter Gryffindor Tower through the Fat Lady's portrait:
caput draconis (PS7)
Latin for "dragon's head".
pig snout (PS9)
Latin for "better luck" (PA5)
scurvy cur (Sir Cadogan thought this one up) (PA11)
oddsbodikins (Sir Cadogan thought this one up too) (PA12)
The most common modern meaning of this word is "an irresponsible, silly person", but a much rarer meaning implies that the person is a mischief-maker if not actually a fiend. Think Peeves for the rarer sense of the word. Perhaps refers to Neville Longbottom who kept leaving passwords lying about.
fairy lights (GF22)
banana fritters (GF25)
Mimbulus mimbletonia (OP11)
A kind of stew or porridge that historically was offered to the British monarch on coronation day by the lord of the manor of Addington, Surrey (NSOED)
Post-Christmas holidays password, after the Fat Lady and her friend Violet drank all the wine in a picture of a group of drunk monks in the Charms corridor (HBP17)
toffee eclairs (HBP20)
quid agis (HBP24)
Latin for "How do you do?"