But Ohanian disagreed and linked to Johnston's profile at the website for the Male Champions of Change, a body that describes itself as working with "influential leaders to redefine men's role in taking action on gender inequality. It activates peer groups of influential male leaders, supports them to step up beside women, and drives the adoption of actions across private sector and government".
Williams has been silent to this point, posting a caption-less photograph of herself and daughter Olympia as the furore unfolded.
The image created uproar in the US with commentators saying it was an example of Australia's "blind racism".
Knight, and his employer, launched an immediate defence, arguing it was a depiction of the tennis star's behaviour and had nothing to do with race.
They doubled down in Wednesday's newspaper, printing a cover with the headline "Welcome to PC World", that featured several of Knight's cartoons with reasons why they could also be branded offensive.
Previous Knight cartoons of Australian politicians and world leaders fill the page, including former prime minister Tony Abbott depicted as Hannibal Lecter with the caption "Banned: Big ears, cannibal mask," and a topless Kim Jong-un with the words "Blocked: Belly fat, Asian stereotype."
Knight's widely condemned cartoon depicting "the world's greatest tennis player spit the dummy" appears in the foreground with the caption: "Vetoed: Large hair and lips, too angry."
"If the self-appointed censors of Mark Knight get their way on his Serena Williams cartoon, our new politically correct life will be very dull indeed," the subhead read.
