Myrtle definitely had a reputation – just look at the nickname. But the forlorn ghost did have heroic tendencies, even in death.

When we first met Moaning Myrtle, the glum ghost seemed to just be a ghoulish distraction in the girls’ toilets. But Myrtle’s morose ways actually ended up being really useful for Harry) and co.

The moaning was actually helpful

Myrtle’s shenanigans ended up giving Harry, Ron and Hermione the perfect den for their secret Polyjuice Potion project in Chamber of Secrets – by making the girls’ bathroom out of bounds. As Hermione explained: ‘It’s been out of order all year because she keeps having tantrums and flooding the place.’

Long before the days of the Room of Requirement, Harry, Ron and Hermione had the perfect, wet hideout for their plans. But sharing a roommate is never easy, as the trio learned when Myrtle laughed maniacally at Hermione when she accidentally turned into a cat.

She was an unlikely agony aunt

Myrtle did have a slightly caring side – even if it was likely born out of nosiness and being an absolutely massive gossip. Her perpetual presence in the plumbing, for instance, made her a consistent confidante for many Hogwarts students. In Harry Potter and the Half-Blood Prince, for example, when Draco Malfoy lamented the grim mission Lord Voldemort assigned him, Moaning Myrtle actually comforted him.

She also arguably saved Draco’s life from serious scarring after Harry cursed him with the dreaded Sectumsempra. Her bellowing of, ‘MURDER! MURDER IN THE BATHROOM! MURDER!’ summoned a nearby Professor Snape, who was able to fix Malfoy’s wounds quickly. After all, he was familiar with Sectumsempra himself.

In typical Myrtle fashion, she couldn’t quite deliver a good deed 100 per cent - she was quick to tell every bathroom in the castle about the gruesomely dramatic story – which was not so great for Harry.

Still of Draco bleeding after being hit by Sectumsempra as Snape uses the counter curse

Her gossiping could actually be handy

Myrtle relished her role as the bearer of bad news – but her tendency to talk a lot inadvertently helped solve a few mysteries. Most importantly, reflecting on her own dramatic death helped to save another student’s life in Chamber of Secrets. Myrtle told Harry: ‘I just remember seeing a pair of great big yellow eyes. My whole body sort of seized up, and then I was floating away ...’

Hearing how Myrtle died confirmed Ron and Harry’s suspicions that a Basilisk lived in the Chamber of Secrets, and was wreaking havoc at Hogwarts. When Harry and Ron asked Myrtle about her death, she was pleased that they cared: ‘She looked as though she had never been asked such a flattering question.’ The description of a yellow-eyed serpent provided key clues about what has happened to Ginny Weasley.

Crucially, Myrtle also told Ron and Harry where she faced her murderer. That led Harry and Ron to uncover the entrance to the Chamber of Secrets. Harry was able to save Ginny, and kill the Basilisk, thanks in part to Myrtle’s candour.

Her inquiring mind could be valuable

Because Myrtle didn’t confine herself to one toilet, she was able to help Harry master a trying task in Harry Potter and the Goblet of Fire – even if Harry was in the bath at the time.

But Myrtle was able to penetrate the white marble and candle chandelier-clad bathroom to watch Harry try to crack the mystery of the golden egg, a trick he needed for the Triwizard Tournament. ‘I’d try putting it in the water, if I were you,’ she told a bewildered – and naked – Harry. Nowhere was off-limits to the versatile Myrtle, particularly when the setting included water.

Myrtle’s interest in Hogwarts students taking baths actually ended up being crucial. By watching Cedric Diggory’s bathtime clue-solving session too, she knew the egg must be put underwater as a result – aiding Harry to solving the clue. Helpful, yes, but... honestly, Myrtle!

Even though Myrtle haunted Hogwarts, she was hardly a bog-standard ghost; she unlocked many of the school’s most important mysteries.

Harry Potter to Fantastic Beasts