Peeves

"GOT YOUR CONK!!!"

- Peeves

Peeves is a poltergeist living in Hogwarts. He's a spirit rather than a physical being, but highly different from the ghosts he's occasionally mistaken for. Peeves is essentially an embodiment of disorder ("an indestructible spirit of chaos" according to a FAQ on Rowling's website), and is constantly causing it, with varying amounts of mischievousness and malice. In appearance he's a small old man dressed in wildly coloured clothing. He's capable of flight and intangibility, like ghosts, but can also affect solid objects and make himself invisible.

He's usually far more annoying than legitimately dangerous, but acts in a wildly unpredictable manner and should not be given the chance to cause serious harm. Peeves does not listen to Hogwarts prefects (to Percy Weasley's great displeasure), professors or anyone else, with the exception of the fearsome Bloody Baron and Dumbledore probably because he had the power to evict Peeves and that he was Headmaster. In the fifth book he chased Umbridge out of the castle with McGonagall's walking stick after she was injured. Argus Filch always wants him to be thrown out and he always cleans out the work done by Peeves. Fred and George Weasley, Dumbledore, the Bloody Baron, McGonagall a little bit, and Nearly Headless Nick are the only people he's listened to.

A scene with Peeves was filmed for the movie version of Harry Potter and the Philosopher's Stone, but was left on the cutting room floor. He has otherwise not appeared in any of the movie adaptations so far.

Peeves is not completely chaotic or without loyalties. During Dolores Umbridge's attempts to take control of Hogwarts in Harry Potter and the Order of the Phoenix that were met with passive insurrection, he actually showed respect for his fellow troublemakers Fred and George Weasley and took their words ("Give her hell from us, Peeves.") to heart as they fled the school, marking possibly the only time Peeves ever obeyed a student.

This was immediately followed by his finest hour, as he went into overdrive and began a rampage of ceaseless mayhem, juggling burning torches over the heads of students, dumping a bag of tarantulas into the Great Hall, and destroying property like never before. It appears that Peeves was actually on friendly terms with the strict Professor McGonagall during this time, due to their common enemy, McGonagall even going as far as to give him hints on how to unscrew a chandelier and apparently allowing him to borrow her walking stick to chase Umbridge from Hogwarts. Later, during the Second Battle of Hogwarts, Filch asks Peeves to be a part of his defence, and Peeves starts causing chaos amongst Death Eaters, showing that he is loyal to the school.