Joel recited a Banjo Paterson poem before the class, titled Mulga Bill's Bicycle.

"Hey, it's Mulga," Matt had said of Joel.

And that was that. Joel had a nickname for life. Funnily enough, Matt scored a cracking nickname in his playing days. He became known as "Waltzing". As in, "Waltzing Matt Hilder".

And Mulga, well, it's become a brand, as well as a name.

Joel is a Sydney-based artist who paints murals and designs T-shirts under the Mulga brand.

His art has been described as bringing to life "a world where tropical bearded men run rampant, lions smoke tobacco pipes, tigers wear diamond sunglasses and gorillas rule the world like some kind of funky planet of the apes".

Joel will attend Warners Bay High School on Tuesday to paint a mural with year 9 students. It's part of a "diversity walls" project run by Hunter Multicultural Communities, which is designed to advocate for harmony, resilience and tolerance.

The Wall Station, a public artwork agency, received funding for the program from the Federation of Ethnic Communities Councils of Australia [geez, what a mouthful].

Participants are encouraged to share stories of how they've experienced or witnessed racism, conflict or threats and how they reacted or were affected.

"It's cool to get art into schools and paint something that kids can connect with, which also has a good message," he said.

He'll be painting "three funky flamingos wearing sunnies".

"Flamingos represent harmony and resilience in different cultures," he said.

"It's about standing out from the crowd, as well. Maintaining your individuality."

Joel was good at art in school, but didn't want to be poor.

"So I studied finance at uni and worked in financial planning for about 10 years.

"Then I just kind of realised that wasn't what I should be doing with my life. I was wasting time. I wasn't passionate about it. I'd kept the same low-level job. So I started to do art a bit more seriously. I started a blog. I started drawing at night."

He made some T-shirts with his art designs and sold them at Bondi markets for a couple of years. The move paid off in an unexpected way.

"Around the time my third kid was born, I quit my day job. That was in 2014," he said.

He became an "artrepreneur".

He's already worked with some big companies including Samsung, Coca Cola, Toyota, Red Bull, Carlton, MTV, Adidas, Microsoft, Slurpee, Virgin Mobile and Jagermeister.

Joel is heading to Japan in a fortnight.

"I work with an agent. I'm trying to take my art to Japan and collaborate with companies," he said.

The connection to this agent in Japan came about because one of her friends was wearing a Mulga T-shirt, having bought it at Bondi markets.

"She worked in licencing and had her own business. She emailed me and flew over to meet me," he said.

"It was so random. I have an agent in China and Korea, as well."

His uplifting and vibrant art is filled with colour.

"It catches the eye. It makes you feel happier," he said.

He uses a lot of black to contrast with the bright colours.

"It makes them pop," he said.

He describes his art as "fun and funky".

Much of his art contains cool-looking animals.

"I give them human characteristics, a bit of character, chuck some sunnies on them, write a story about them," he said.

"Everyone loves animals. It's always good when you're creating art in a theme that people also like."

Joel adds playful poems to his art.

"I like making people laugh. I don't really like being serious. The poems give the artwork another element," he said.

They also hark back to his nickname and the day he recited Banjo's famous poem.

People in glass houses, of course, shouldn't thrown stones. But what the heck. Reader John King sent us this picture of a John Renshaw Drive sign with a typo.

"Just thinking about whose responsibility it was to check out the $50 note for spelling mistakes. Could it have been the same person that checked out the road sign opposite the service station near the end of the M1," John quipped.