He made his way unseen all the way up to the entrance of Gryffindor Tower and changed back to his true form. However, The Fat Lady would not let him in without the password. Frustrated, Black slashed her portrait and fled.
Sirius broke into the Boys' Dormitory and walked towards Ronald Weasley's bed in his search for Peter Pettigrew, who had, for a dozen years, disguised himself as Ron's pet rat, Scabbers. Ron woke up, hearing some scratching noises, and saw Sirius in the room with a knife that he was holding as defence against Peter.
Until the climax of Prisoner of Azkaban, Lupin believed Sirius Black was guilty of murdering 12 Muggles, betraying Lily and James Potter, and killing Peter Pettigrew. He eventually discovered the truth — that Sirius was innocent, and the very much alive Peter was the traitor.
Fundamentally, he was a good person. He fought for what was right and was unafraid to stand against Voldemort. He joined the Order of the Phoenix not once, but twice. Despite being a pure-blood, he didn't believe that he was superior to other witches, wizards and Muggles.
History. On 31 October 1993, Sirius Black attacked Fat Lady's portrait in a vain attempt to gain entrance to Gryffindor Tower. Scared, the Fat Lady ran away hiding in other paintings, including this one, where she hid behind the hippopotamus.
Why Did Sirius Slash the Portrait of the Fat Lady? - Harry Potter Theory
Who actually attacked the Fat Lady?
When the Gryffindors got back, they saw the damage and Peeves revealed Black to be the attacker, and that he had seen the Fat Lady fleeing through other portraits.
When Sirius first breaks into Hogwarts in Prisoner of Azkaban, he doesn't know the password to get into Gryffindor Tower. In anger he rips the Fat Lady's portrait. While Sirius' frustration is understandable, he was a Gryffindor. He knows the fat lady is only doing her job and keeping his beloved house safe.
The last known surviving bearer of the family name, Sirius, is murdered by his cousin Bellatrix Lestrange in Harry Potter and the Order of the Phoenix.
Peter Pettigrew's betrayal of the Potters and allegiance to Voldemort was a result of his unhealthy admiration for James and desire for power. Sirius Black was believed to be the Potters' Secret Keeper, but he secretly switched with Peter Pettigrew, who turned out to be a mole.
He was framed. Most of everyone in the wizarding world believed that he had murdered people. Peter Pettigrew had become the secret keeper for James and Lily when they had found out Voldemort was looking for them.
And Remus was in love with Sirius (also hopelessly, because Sirius only had eyes for James). Then James was killed, Sirius was imprisoned, Remus was outcasted, and Peter was ratatouilled.
Draco, who implies that he is aware of how Sirius Black was supposedly involved in the deaths of Harry's parents, also taunts Harry about the impending threat of Black: "If it was me, I'd want revenge. I'd hunt him down myself."
Black was able to maintain his sanity due to his knowledge of his innocence, a non-happy thought that the Dementors could not take. It was only this that allowed him to maintain his powers to transform, and what made the escape possible.
Upon the dais is a stone archway, covered with a tattered black veil. Sirius is hit by Bellatrix's curse, and his stunned body arcs into the air and floats through the archway, disappearing behind the veil. Harry expects Sirius to reappear on the other side, but he never does.
Sirius left all his belongings, including Kreacher, to his godson. Harry, who had no desire to have anything to do with Kreacher, ordered him to work in the kitchens at Hogwarts with the other house-elves at Dumbledore's suggestion, where he and the other house-elves could keep a close watch on him.
Peter Pettigrew — the man did a full 360. He first betrayed the Potters to Voldemort, and then later betrayed Voldemort by showing even just a brief moment of mercy to Harry at Malfoy Manor.
Scabbers was Ron Weasley's pet rat. Passed down throughout the family, by the time he came to Ron, Scabbers was living up to his name with patchy fur and a distinct preference for sleeping.
Remus fought at the Battle of Hogwarts on 2 May 1998, during which his wife was murdered by Bellatrix Lestrange. Remus was also murdered by Death Eater Antonin Dolohov, during the first half of the same battle. His death was possibly avenged by Filius Flitwick.
During the final battle, Bellatrix was the last Death Eater standing. She was eventually killed in a duel by Molly Weasley after her attempted murder of Ginny Weasley. Before her death, Bellatrix secretly gave birth to an illegitimate daughter named Delphini, whom she conceived with her beloved master, Lord Voldemort.
Of course Bellatrix wanted to kill Sirius. She's a crazed psychopath who enjoys killing, and Sirius openly defied everything Bellatrix believed was right.
Originally Answered: What is the first password for the Gryffindor common room? The first one that we see in the books is “Caput Draconis”. It is Latin for “head of the dragon”.
Dumbledore's lack of belief that Sirius is innocent is also suspect. Sirius was a member of the Order of the Phoenix which fought against Death Eaters, but Sirius also was as close to James as a brother, the Potters even took him in when he ran away from home.
In his Animagus form, James was a tall and powerful red stag, large enough to subdue an adolescent werewolf alongside Sirius's bear-like black dog form.
