Borobi, a blue koala who likes surfing, has received a warm welcome since making his debut. 

But Troy Sizer, who entered his drawing of a blue koala wearing the iconic lifesaver's red and yellow cap and board shorts into the mascot competition, has alleged that Borobi bears a striking resemblance to his design.

"I was eagerly watching it on TV and my heart sank when I saw the character descending from the helicopter because I could see it was a blue koala and a surfing koala at that," Sizer, who lives in Gilston on the Gold Coast, told News Corp.

"I hate reliving that moment in my mind, it makes me feel sick to the stomach."

Borobi performed for crowds of thousands in a routine aired live on Channel 7's Sunrise programme after being officially unveiled to the public at a ceremony held to coincide with two years until the Opening Ceremony of Gold Coast 2018.

The idea of Borobi was credited to Brisbane school teacher Merrilyn Krohn.

Sizer, though, claimed it owed more to his design.

He had called the mascot Nobby and had specifically detailed that it should be blue because that would match the colour of the ocean. 

“They showed the original illustration by the artist, which is a very nice illustration, I’m not belittling her work, but it was a standard grey koala and it looked significantly different to the final mascot," said Sizer.

“It makes me wonder, how many blue surfing mascots did they receive?”

A spokesman for Gold Coast 2018 said they had received 182 koala designs out of a total entry of 4,000.

"At no point during Borobi's development was Troy's design presented to the creative design team, so they could not have possibly drawn inspiration in any way from it," he told News Corp.

In 2014 in a Facebook post Sizer had claimed the Socceroos kangaroos mascot had been borrowed at least partially from a design he submitted.

Sizer does not plan to take legal action, he promised. 

“There’s nothing financial, it’s purely the recognition of being involved and contributing towards this character," he told The Project, a  talk show and news-current affairs television on Channel 10. 

“I really do feel quite empty about what’s happened but I genuinely think the final character looks great and I really believe we need to get behind it as the Commonwealth Games are going to be the biggest thing that has ever happened to this city,”