McKee wrote and animated thirteen Mr Benn episodes for the BBC in the early 1970s. These episodes were repeated many times over the years, and many people retain fond memories of him. The episodes were narrated by Ray Brooks, and the music composed by Don Warren.
Although Smasher Lagru features in The Gladiator, he does not appear in The Clown as the book in which he made his debut, 123456789Benn was not adapted for television – thus it would have been strange that he and Mr Benn already knew each other. The Hunter was also slightly altered; the book Big Game Benn features several hunters, but only one appears in the television episode.
McKee has not benefited financially to the extent he might have: "I signed a contract where I only got a one-off payment and no repeat fees, but I've done quite well from a number of other things and I'm still exhibiting paintings." Unfortunately, according to Mr Benn's Little Book of Life, very little of McKee's original artwork created for the television episodes exists today, as a majority of it was thrown into a rubbish skip in the 1970s.
After over thirty years, a brand new Mr Benn episode was screened for the first time on 1 January 2005, on the UK channel Noggin. The episode was based on McKee's 2001 book Mr Benn - Gladiator.
The series was voted the sixth most popular children's television programme in the 2001 Channel 4 poll 100 Greatest Kids' TV Shows.