Bartemius "Barty" Crouch Junior was a wizard and the son of Bartemius Crouch Senior. He became an ardent follower of Lord Voldemort in order to become a Death Eater and Dark wizard in his teenage years. He was the first escapee of Azkaban prison in its almost 300 year history, though only his father, late mother and the family house-elf knew until 1995, when it was revealed to Albus Dumbledore, Harry Potter, Minerva McGonagall and Severus Snape whilst Crouch was under the influence of Veritaserum. In 1981, shortly after Voldemort's first defeat, Crouch allegedly participated in the capture and torture of Frank and Alice Longbottom along with the Lestranges, using the Cruciatus Curse to drive the two Aurors to insanity. Crouch and his comrades were sentenced to life imprisonment in Azkaban for their crimes by his own father.

Crouch and his parents hatched a plot under which Crouch's mother would take his place in Azkaban, using the Polyjuice Potion to disguise herself. She died and was buried in Azkaban, with the result that the wizarding world believed that Crouch himself was dead. Crouch spent the following years living under his father's Imperius Curse. He eventually broke free with the help of Voldemort, who had learned that Crouch was still alive, making him enter the Dark Lord's service again. He then disguised himself as Alastor Moody, former Auror and the 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 was chosen as a champion, and turned the Triwizard Cup into a Portkey that transported Harry and Cedric Diggory to Voldemort.

Character is based off the 2005 movie, Harry Potter and the Goblet of Fire, and was played by actor, David Tennant.