Peeves the Poltergeist

Peeves the Poltergeist is a recurring character in the Harry Potter film series from 2001 to 2011, played by comedian Rik Mayall.

He was originally intended to be cut from the first film, however director Chris Columbus changed his mind at the last-second and had the crew undertake some final edits of his scenes to satisfy his vision for the character.

Harry Potter and the Philsopher's Stone (2001)
Peeves makes several brief appearences, predominantly during the Start-of-Term Feast at the beginning of the film.

At the event, Peeves placed whoopie-cushions under the seats of several students, including Neville Longbottom's. He was also berated by the ghosts in attendance, including Nearly Headless Nick, to which Peeves responded by blowing a raspberry and mockingly impersonating him by also tearing his head off halfway.

Ron Weasley speculated Peeves as the culprit behind the Mountain Troll's release, though this would later be disproven. Later, as Harry Potter, Hermoine Granger, and Ron were on their way to obtain the Philsopher's Stone, they encountered Peeves. Luckily, they were masked under the Invisibility Cloak, and as such Harry impersonated Dumbledore, scaring off Peeves. He later made a cameo at the end of the film, firing off party poppers in celebration.

Harry Potter and the Chamber of Secrets (2002)
Peeves was one of the attendees at Nearly Headless Nick's deathday party, dressed in ludicrous fashion. He acted rather civilised, surprisingly, apart from his taunting of Moaning Myrtle, whom he threw moudly peanuts at.

Harry Potter and the Goblet of Fire (2005)
Peeves returned following his absence in Harry Potter and the Prisoner of Azkaban (2003), where he was shown dropping water balloons on students prefacing the welcoming feast in the entrance hall, with Ron among those falling victim. Later, during the Yule Ball, he ruined a couple's romantic moment by hiding in a nearby suit of armour and making kissing noises and impersonating Clark Gable from Gone with the Wind; when the boy grew angry and loudly yelled at Peeves through the helmet, Peeves kicked the boy in his backside as he turned to walkaway. He also butt in with a couple dancing, taking the girl and performing the tango complete with roses in his mouth.

Harry Potter and the Order of the Phoenix (2007)
Peeves arrived during Fred and George Weasley's firework display in brightly-coloured pajamas, woken up by the commotion, however he was quickly starstruck by the event and driven to tears. As the brothers fled, Peeves saluted them as they commanded him to further disrupt the reign of Dolores Umbridge.

In rebellion, Peeves began vandalising the walls of the school with insults directed toward Umbridge, as well as unleashing a swarm of tarantulas onto the Great Hall and juggling burning torches over the heads of students. As people ran toward the exits, they fell victim for his tripwires, falling down in piles as buckets of yogurt and glitter were poured onto them. As Peeves began to unscrew the chandeliers overhead, Professor Minerva McGonagall calmly informed him, amidst the panic, that he was unscrewing them the wrong way as Peeves smiled in response.

Harry Potter and the Deathly Hallows Part II (2011)
Peeves returns near the end of the film during the Battle of Hogwarts, handing out Snargaluff pods to students before flying overhead and dropping some on attacking Death Eaters. Peeves was present for Voldemort's defeat, and led celebratory chants afterward.