David Walliams said he hopes to become the oldest person to swim the English Channel as he was honoured at Buckingham Palace.
The TV star and author was watched by his mother Kathleen and nephews Eddie and Frankie when he was presented with an OBE by the Princess Royal in recognition of his services to charity and the arts.
The comedian joked that he will celebrate the royal accolade with a lunch of fried chicken, before clarifying: "I like Nando's but not today, not in my morning suit".
Walliams has become one of the most loved children's authors in a generation, and has also generated millions for charity, swimming the English Channel in 2006 and taking on the Strait of Gibraltar in 2008.
In 2011, he raised £2 million for Sport Relief by completing a challenging 140 miles down the River Thames.
Asked about his next fundraising feats, he said: "I don't have major ones because the problem is every time you do a challenge it's got to be greater than the last one, and the last one, which was swimming the Thames, really did me in. I've got back problems, shoulder problems.
"And also I'm older, I'm 46, so I don't know what I could do that's greater than what I've done and still live to tell the tale.
"I'd like to do something, I've always thought I'd like, if Comic Relief and Sport Relief are still going in 25 years, being the oldest person to do a challenge, do a challenge at 70, but who knows what shape I'll be in."
Asked if he would consider repeating the Thames challenge, he said: "Not that one no, but I'd quite like to have a go at the Channel at 70.
"But I don't know, it may be good to leave those things, not revisit things you were successful at - if you tried to swim the Channel again and failed it would be very disappointing wouldn't it?"
Walliams said it was "a bit nerve-wracking" to be invited to the Palace because "you feel you might say or do the wrong thing".
He is taking a day off from filming in Glasgow for a BBC TV adaptation of his children's book Grandpa's Great Escape, due to hit screens at Christmas.
He said: "I love what I do. I feel very lucky, very privileged to be in the situation I'm in, and get to do the things I want to do.
"I remind myself every day how lucky I am to be working with incredible people, especially when you get to work with a childhood hero like Sir Tom Courtenay, someone whose career you've admired for so many years. I don't take any of it for granted, especially not today."
He said there was "no way" he could not have invited his mother to share the special day, adding: "She's probably prouder than I am".