He is raised by his single mum and has a unsightly birthmark on his face. But our piglet also has a pure heart. He loves his mum, and his mum loves him.
The lovable piglet was created by local illustrator Alice Mak Ka-bik and writer Brian Tse Lap-man, an artist couple. McDull was - at first - only a supporting character to his cousin McMug, in a comic strip in a children's magazine.
As his popularity rose he became a star in his own right: first the main character in some of the couple's illustrated story books, and later the protagonist in their first movie, My Life as McDull, in 2001.
Now, the couple has brought him back for a fifth cinematic adventure, McDull, The Pork of Music.
"This time the movie is going to be about music," illustrator Mak says of the title.
This time around McDull shows up in his average-student role, but with an extraordinary voice.
Together with his classmates at Springfield Flower Kindergarten, he forms a choir and sings touching hymns all over the place - from Guangzhou to Macau.
Although it first started out as a children's story, the McDull series has grown into a full-fledged movie production, as Tse decided to develop the character.
At first, Tse wanted to write a warm-hearted story about a family moving to a new area, for a children's publication. But this simple concept started to gain momentum and depth as the years passed and Tse matured as a writer.
"McDull became a way for Brian to explore social issues," Mak says, on behalf of her husband, who rarely speaks to the media.
For example, in McDull, The Pork of Music, many mothers are seen tinkering with their computers and smartphones to check on the stock market. "Compared with 10 or so years ago, a lot more Hongkongers, especially housewives, invest in the stock market these days," Mak says. "That's the reality."
Although Mak denies the movie deliberately highlights Hong Kong's pressing property price problem, a character in the movie whinges about the many fancy skyscrapers built in the city.
"It's another reality," Mak says. "Eighty per cent of my friends experience the same problem. They are either looking for a new house, have just moved to a new one, or are pondering whether they should sell their properties".
To Tse and Mak, McDull is a social experiment; he's a character with a good heart. But instead of placing him in a cheesy fairy tale setting, they put him to the test to see how he would react if he lived in the same cut-throat society we do. Mak says: "When you're not particularly bright and don't have a special edge, but you need to survive in this competitive society, what would you need?"
The past four McDull movies all had uniquely different storylines. But they all shared the same template: a simple plot intertwined with bits and pieces of comedy.
McDull, The Pork of Music is going to be different.
"It is a very complete story," Mak says. "But despite its 'completeness', it's still very rushed - and you have to pay attention to the story's development."
Mak says the biggest difference actually comes thanks to another local illustrator Yeung Hok-tak's involvement. Yeung is famous for his crudely drawn characters. He was responsible for drawing most of the human-shaped figures and some of the background scenes in the movie.
"The previous movies were slower, with a tingle of romance and bitterness," Mak says.
"But this time, even though there are heartbreaking scenes, and in the end you'll witness some time-whizzing shots, the audience can still enjoy Yeung's fast-paced and colourful style".
A scene from the upcoming film.
Though the McDull series has made a leap to explore more grown-up issues, its dearest and original supporters - children - will never get left behind. Mak and Tse craft their movies so that different audiences can interpret them differently.
For this music-driven latest adventure of our favourite piggy, every child can see their problems disappear as they listen to lovable tunes belted out by their porcine hero. The idea is to help children leave happier after watching the movie, Mak says.
"Meanwhile, for adults, their old kindergarten may be about to be closed down - like Springfield Flower in the movie - and when they see this, they may feel really upset."
One more thing: you will never find a definite ending in any of the McDull's movies because Mak says Tse likes leaving some loose ends for audiences to puzzle over.
Making animations is not an easy job, but Bliss Concepts, the small company that produces McDull's books and movies, has sought to improve step by step.
Every new McDull movie has been bigger and better than the previous one, and McDull, The Pork of Music is the largest and most ambitious yet - and the most time-consuming: it took three years for the company's 10members of staff to complete it. Mak can now breathe a sigh of relief.
The illustrator says that the casting and recording bits seemed to take forever. "It's very hard to find kids that sound natural these days because they all learn how to read poems in school," she says.
For McDull, they needed to find a child actor who, first of all, had a coarse voice that resembled the piglet's, and second could recite his lines in a natural and unpretentious manner.
It almost became a practical joke as they needed to train a child to sound naturally without effort - and to do that while reading a lengthy script.
As if that wasn't not bad enough, Mak and Tse had to cast voice actors in Putonghua, too, as the movie will also be screened on the mainland.
Mak said that the bilingual actor who voiced McDull in the previous movie still has the same voice so they called him in again for this movie. But that still meant the team had to travel repeatedly between Hong Kong and the mainland to get the song recording done.
Yet all that hard work over the years has been worth it. From his humble origins as a minor character sketched on paper, McDull has grown to become Hong Kong's most successful animation icon.
My Life as McDull won the feature film award in the Annecy International Animated Film Festival in 2003. So the adorable piglet has proved a real success for his creators.
Yet that doesn't mean Mak doesn't like other characters. If she could pick another of her creations to star in a film, she already has a character in mind. "I'd choose Ah-Fai [the turtle], who's also really popular."
McDull, The Pork of Music opens on Thursday