Fred and George Weasley

Fred and George attend Hogwarts from 1989 to around springtime of the 1996 school year, and are two years ahead of Harry, Ron, and Hermione Granger. They are the school clowns and troublemakers, more interested in inventing new pranks than studying. Despite their unimpressive academic record, they show a high degree of knowledge and skill in creating magical jokes and tricks. Both play as Beaters on the Gryffindor Quidditch team and are very talented players.

Fred and George care little for Prefects or rules, which contributes in their eventual falling out with their older brother Percy. Their appearances and personalities are so indistinguishable that they can fool even their mother. Fred appears slightly more aggressive/take-charge than George, which is most apparent in Harry Potter and the Goblet of Fire where George is more cautious about blackmailing Ludo Bagman and, unlike Fred, is not mentioned as having a date at the Yule Ball. In Harry Potter and the Goblet of Fire, Fred's date was Angelina Johnson. Fred is also seen to speak a lot more often than George.

In Harry Potter and the Goblet of Fire, Fred and George begin selling their own jokes by owl order, under the name "Weasleys' Wizard Wheezes." They play a prank on Harry's first cousin, the fat, bullying Dudley Dursley by "accidentally" dropping a Ton Tongue Toffee – Dudley, a glutton on a forced diet, soon has a four-foot-long tongue protruding from his mouth. At the Quidditch World Cup they impress Ludo Bagman, Head of the Department of Magical Games and Sports at the Ministry of Magic, with their fake wands.

Their ambition in life has always been to run their own joke shop. Harry makes this possible by giving them his winnings from the Triwizard Tournament.

The pair provide Harry with useful assistance throughout the series; in Harry Potter and the Chamber of Secrets they and Ron help him escape his house arrest at Privet Drive. In Harry Potter and the Prisoner of Azkaban they give him the Marauder's Map. In Goblet of Fire, they try to encourage Harry and Ron to find dates to the Yule Ball by letting them see Fred ask Angelina Johnson. They also help Harry in Order of the Phoenix when Harry wishes to talk with his godfather, Sirius Black, by creating a distraction, leaving Hogwarts in a state of chaos. They were also members of Dumbledore's Army, a group started by Harry, Ron, and Hermione to teach practical instruction in Defence Against the Dark Arts, which Umbridge had removed from that course's curriculum.

Later that year, they are banned from Quidditch and decide to abandon formal education; before leaving, though, they pay tribute to Dumbledore by waging a prank war against the dictatorial Dolores Umbridge. Threatened with flogging for conjuring a swamp in a corridor, they depart on broomsticks, yelling to Peeves in the process, "Give her hell from us, Peeves."

It is stated by several characters, including Professor Flitwick and Hermione, that despite their poor grades and meager number of O.W.L.s, the Weasley twins are extremely proficient wizards, capable of sophisticated magic (such as spells for high-quality daydreams). This is evidenced by the large number of inventions they have created and by Fred's ability to transform Ron's teddy bear into a spider even before he was old enough to attend Hogwarts.

As they leave, the twins inform their fellow students of their new shop in Diagon Alley and offer discounts to students who will likewise harass Umbridge. The swamp, meanwhile, remains for some time, since Umbridge is unable to remove it and no other teacher particularly wishes to. After Professor Umbridge is driven from the school, Professor Flitwick removes it, but leaves a small bit as a tribute to the Weasley twins.

In The Half-Blood Prince, Fred and George continue to run their very successful joke shop, Weasleys' Wizard Wheezes, out of Diagon Alley with the help of at least one employee. At the beginning of the school year, they have a large advertisement for a potion called "U-No-Poo," poking fun at the common euphemism of Lord Voldemort in the wizarding community. Their import item, Peruvian Instant Darkness Powder is used by Draco Malfoy to escape the detection of former DA members. It is unclear if Fred and George have joined the Order of the Phoenix as they wished during the previous book. Their wares have twice been indirectly responsible for injuries suffered by their siblings: their Instant Darkness Powder allowed the werewolf Fenrir Greyback into Hogwarts, where he proceeded to savage Bill Weasley; and a love potion sold by them was ingested by Ron Weasley, requiring him to seek an antidote from the Potions Master, Professor Slughorn — who then accidentally poisoned him.

Though Mrs. Weasley initially disapproved of their enterprises, she realised they had a natural gift and passion for their business and has since raised no objections. In fact, she is now rather impressed with how successful the twins have become since leaving school. According to their proud younger brother Ron, "they're raking in the Galleons!"

In Harry Potter and the Deathly Hallows, Fred and George are members of the Order of the Phoenix and serve as two of Harry's six decoys when he escapes Privet Drive. George loses one of his ears to Snape's Sectumsempra curse (which was aimed at a Death Eater's wand hand, but missed). Mr. Weasley and Fred force their way into The Burrow – Kingsley Shacklebolt didn't want to let them in until they proved who they were – and Fred is described as being lost for words for the first time since Harry met him. He remains pale and terrified, until George wakes up. When Mrs. Weasley asks George how he feels, he replies, 'Saintlike.' After some general confusion, he clarifies, saying that he is 'holey.' This causes his mother to sob harder, while Fred comes to himself and says that the joke was pathetic. As the injury was caused by dark magic, it cannot be repaired. George remarks that, at the very least, he and his brother became much more distinguishable and their mother will be able to tell them apart now.

During this novel, every member of the Weasley family is being watched by the Ministry of Magic (now led by Death Eaters). It is impossible for Fred and George to return to their shop in Diagon Alley to sell their products, so they begin to run another owl-order business out of their Auntie Muriel's house.

During the Battle of Hogwarts, Fred is killed in an explosion. Before his death, Fred reconciles with his estranged brother Percy, who arrives at Hogwarts to participate in the fight and apologises to the family for not believing them. Percy, who was right next to him, was distraught, and refused to leave Fred's body. Fred died with a smile frozen on his face, as moments before death he was laughing at Percy for making a rare joke. Percy returns to the fight only after Harry helps him carry Fred into a niche where a suit of armor stood before it went to join the fight. Fred is the only member of the Weasley family who dies, and plays a factor in his mother's duel with Bellatrix Lestrange.

There are only two mentions of George after this. The first comes when Harry sees that the dead have been laid out in a row in the Great Hall. He can't see Fred's body, because he is surrounded by his family. George is only briefly described as kneeling at his twin's head. The second mention is when George and Lee Jordan defeat the Death Eater Yaxley.

According to Rowling, she always knew, intuitively, that Fred would be the one of the twins that would die, but she doesn't exactly know the reason.[4] Although not mentioned in the novel, Rowling said in a web chat that George never does fully get over Fred's death. However, he goes on with his life, turning Weasleys' Wizarding Wheezes into a "money spinner" with Ron.[5] George later names his first child with Angelina Johnson after his twin.[6]