Sir Cadogan

Sir Cadogan is a short, squat knight in a suit of armor who inhabits the moving portraits of Hogwarts. He first appears when Harry, Ron, and Hermione become lost while searching for the North Tower and the Divination classroom. Sir Cadogan rides a fat, dappled-gray pony and is covered in grass stains from repeated falls. Upon seeing the three students, he immediately challenges them as "villains" trespassing on his "private lands," draws his sword, and brandishes it violently, only to overbalance and land facedown in the grass. Despite his ineptitude, he offers to guide them on a "quest" to find their goal, running through various paintings and shouting encouragement. He introduces himself with the cry, "Farewell, my comrades-in-arms! If ever you have need of noble heart and steely sinew, call upon Sir Cadogan!" Ron mutters that they will call him "if we ever need someone mental."

Role as Guardian of Gryffindor Tower

After Sirius Black slashes the Fat Lady's portrait on Halloween night, none of the other pictures want to take on the dangerous job of guarding the Gryffindor common room entrance. Sir Cadogan is the only one brave enough to volunteer. He is installed as the temporary guardian, but his tenure is chaotic. He spends half his time challenging people to duels and the rest thinking up ridiculously complicated passwords, which he changes at least twice a day. Students find him a "complete lunatic," but Percy Weasley explains that no one else would take the post. Sir Cadogan's first password is "Scurvy cur," and he later uses "Oddsbodkins." He also enjoys a Christmas party with monks, previous headmasters, and his pony, toasting with mead.

The Security Breach

Sir Cadogan's most significant action is also his undoing. When Sirius Black approaches the portrait hole, Sir Cadogan lets him in because Black has the passwords. Black had obtained them from a piece of paper that Neville Longbottom had written them on and then lost. Sir Cadogan proudly tells Professor McGonagall, "He had 'em! Had the whole week's, my lady! Read 'em off a little piece of paper!" This breach allows Black to enter the Gryffindor boys' dormitory with a knife, an event that terrifies the entire house. As a result, Sir Cadogan is immediately fired. His portrait is taken back to its lonely landing on the seventh floor, and the Fat Lady, after being expertly restored, returns to her post with extra protection from security trolls.

Narrative Significance

Sir Cadogan functions primarily as comic relief, his exaggerated chivalric posturing and incompetence providing a humorous contrast to the increasingly dark events of the story. However, his role as a security guard is also a plot device that directly enables Sirius Black's dangerous intrusion into Gryffindor Tower. His failure underscores the theme of security and trust that runs through the book, as the castle's defenses are shown to be only as strong as their weakest link—in this case, a boastful but foolish knight and a forgetful student. His brief tenure also highlights the general fear and disruption caused by Black's presence at Hogwarts, as even the paintings are too scared to take the job.