Alastor "Mad-Eye" Moody
Background
Alastor "Mad-Eye" Moody is an Auror. Half of the cells in Azkaban are filled with dark wizards he caught.
During the events of Harry Potter and the Goblet of Fire (2005) played by Brendan Gleeson
Albus Dumbledore, Professor Snape and Professor McGonagall find the real Moody locked in a chest and the fake Moody fully transforms back to Barty Crouch Junior.
During the events of Harry Potter and the Order of the Phoenix (2007) played by Brendan Gleeson
Harry Potter wakes up to someone opening the door to his room and Nymphadora Tonks, Alastor, Kingsley Shacklebolt, Elphias Doge, and Emmeline Vance walk in and Alastor tells him they are here to save him. Kingsley tells Harry that Dumbledore persuaded Cornelius Fudge to hold a trial before expelling Harry. They go to Grimmauld Place where Sirius Black is having a meeting with Mr Weasley, Professor Lupin, McGonagall, Professor Snape and Mrs Weasley. Kingsley hands Harry a newspaper where Fudge is accusing him and Dumbledore of lying about Voldemort. Sirius tells Harry that Voldemort has been trying to recruit followers and that Voldemort is trying to get something he didn't have last time. Later, the Order of the Phoenix arrive at the Department of Mysteries and a battle starts between them and the Death Eaters. Bellatrix Lestrange casts the Avada Kedavra spell against Sirius, hurtling him towards the Veil, which absorbs him.