Age: 42.
Appearance: Genetically engineered for light entertainment.
You mean the guy from Little Britain? That's him. Although the sketch show is fast becoming a footnote in his ridiculous career.
What's ridiculous about his career? What isn't? He's a comedy actor/scriptwriter/Britain's Got Talent judge/children's author/long-distance swimmer. Each one of those is enough to fill some people's entire lives.
But he's still mainly a comedian, isn't he? For now, what with his sitcom Big School on BBC1 as we speak, but probably not for long.
What's happened? One of his sidelines has become so successful it has started to dwarf everything else.
He's become the world's best talent show judge? No, not that. That's clearly Amanda Holden.
He's become a world-class long-distance swimmer? Again, no. Although he's pretty impressive. Walliams has swum the English Channel, the Strait of Gibraltar and the entire length of the Thames for charity.
Then what? He's become a multimillion-pound children's author. According to one publisher he's "the most successful children's book writer for years" and "the Roald Dahl of his generation".
Seriously? Yep. He has sold over 2.5m copies of his books since the first, The Boy In The Dress, was published in November 2008, and his five books so far have raked in over £13m.
Wow. What makes them so popular? Apart from the fact they have his name on them?
Yeah, apart from that. Probably the good old-fashioned mix of weirdness, broad and silly humour and clear and simple life lessons.
Such as? In Billionaire Boy, about the world's richest 12-year-old, that money won't buy you friends. In Gangsta Granny, that our grandparents have lived whole lives we know nothing about. And, in Ratburger, that it's bad to turn pets into burgers but sort of OK for rats to eat people.
Some of those lessons sound less useful than others. Well, yeah. He's the new Roald Dahl, he's not the new bible.
Do say: "He's the author formerly known as 'I'm a laydee.'"
Don't say: "I thought he was just a swimmer."
