Barthemius "Barty" Crouch Jr. (c.1962 – c.1996) was a wizard and the son of Barthemius Crouch Sr. He became a staunch follower of Lord Voldemort before becoming a Death Eater and Dark Wizard in his teenage years. He was the first to escape from Azkaban prison in its nearly 300-year history, although only his father, his late mother, and the family elf survived until 1995. It was known, until it was revealed to Albus Dumbledore, Harry Potter, Minerva McGonagall and Severus. Snape while Crouch was under the influence of Veritaserum.

 In 1981, shortly after Voldemort's first defeat, Crouch apparently participated in the capture and torture of Frank and Alice Longbottom along with the Lestranges, and used the Cruciatus Curse to drive the two Aurors insane. Crouch and his comrades were sentenced to life in Azkaban by his father for their crimes.

 Crouch and his parents devised a plan in which Crouch's mother would take his place in Azkaban and use Polly Joyce's potion to disguise herself. He died and was buried in Azkaban, leading the wizarding world to believe that Crouch himself was dead. Crouch spent the next few years under his father's "Imperius Curse". He was eventually released with the help of Voldemort, who had learned that Crouch was still alive, forcing him to return to the Dark Lord's service.

 He then disguised himself as Alastor Moody, a former Auror and new Defense Against the Dark Arts professor at Hogwarts during the 1994-1995 school year. In this role, Crouch fixed the Triwizard Tournament so that Harry Potter would be crowned champion and turned the Triwizard Cup into a Portkey that transported Harry and Cedric Diggory to Voldemort. Shortly after, his identity is revealed and Crouch is given the Dementor's Kiss by a Dementor that Cornelius Fudge brought with him.