 Knight worked as an editorial cartoonist for "The Herald", and later for the "Herald Sun" after "The Herald" and "The Sun" were united in 1990.In 1999 Knight, alongside Bill Leak and other male political cartoonists, were criticised by the Labor Party's deputy leader, Jenny Macklin, who argued that cartoons such as those by Knight and Leak showing Meg Lees in sexual relations with John Howard were demeaning to women politicians.Knight created the children's character "Leuk the Duck" (derived from "leukemia"), a mascot for the Challenge cancer foundation which has subsequently been used in the organisation's educational material.