Harry Potter: The Prisoner of Azkaban & The Goblet of Fire

Explanation: Sirius Black, the first person to break out of Azkaban in 300 years. He transformed into his Animagus form (a black dog) to slip through the bars, a form Dementors cannot sense.

Explanation: The Dementors, cloaked creatures that feed on human happiness. Their "Kiss" sucks out the victim's soul. They have no permanent allegiance and join Voldemort in Book 5.

Explanation: Remus Lupin, bitten as a child by Fenrir Greyback. He resigns at the end of Book 3 for fear of hurting students. He marries Nymphadora Tonks in Book 6 and dies at the Battle of Hogwarts.

Explanation: A Hippogriff, specifically Buckbeak. Hagrid explains you must bow first to earn its respect. Draco insults him and gets injured, leading to Buckbeak's trial, saved by Hermione and the Time-Turner.

Explanation: A Time-Turner, lent by McGonagall via the Ministry of Magic. Each turn rewinds one hour. At the end of Book 3, Hermione and Harry use it to save Sirius and Buckbeak simultaneously.

Explanation: Peter Pettigrew (Wormtail), an Animagus rat who betrayed the Potters and faked his own death 12 years earlier by cutting off his own finger. He's been hiding with the Weasleys, waiting for Voldemort to return.

Explanation: The Marauder's Map, given to Harry by Fred and George. To activate: "I solemnly swear that I am up to no good." To clear: "Mischief managed." It's the map that reveals Scabbers' real identity to Lupin.

Explanation: Ireland, 170 to 160. Paradoxically: Bulgaria loses the match but their Seeker Viktor Krum catches the Snitch, choosing to end the match to avoid a humiliating rout.

Explanation: Hogwarts (host), Beauxbatons (France, led by Madame Maxime, a half-giantess) and Durmstrang (Northern Europe, led by Igor Karkaroff, a former Death Eater). Other major magic schools (Ilvermorny, Mahoutokoro) don't compete.

Explanation: The Hungarian Horntail, the most dangerous of the 4 tournament species. Harry is the only champion to fly around his dragon on his Firebolt, snatching the golden egg between its claws. He ties for first place with Krum.

Explanation: Harry Potter and Cedric Diggory for Hogwarts (Harry entered "illegally" by Barty Crouch Jr), Fleur Delacour for Beauxbatons, Viktor Krum for Durmstrang. The Goblet normally spits out one champion per school but spits out 2 for Hogwarts.

Explanation: In a graveyard in Little Hangleton, the Muggle village where his father's family lived. The ritual requires "bone of the father, flesh of the servant, and blood of the enemy", the remains of Tom Riddle Sr, Wormtail's sacrificed hand, and Harry's blood.

Explanation: Barty Crouch Junior, an escaped Death Eater, using Polyjuice, he keeps the real Moody prisoner in a magical trunk. His plan: make Harry win the Tournament so the Cup-Portkey teleports him to Voldemort.

Explanation: S.P.E.W. (Society for the Promotion of Elfish Welfare). Hermione knits hats and socks for the Hogwarts kitchen elves, but they take it as an insult, offered clothing = freedom, and they don't want to be freed.

Explanation: A beetle. That's how she spies on her victims for her sensationalist articles in the Daily Prophet. Hermione discovers this at the end of Book 4 and blackmails her into stopping writing for a year.