The Little Britain creator admits he hates the way he looks but would never consider going under the knife to improve his image.
Walliams also reveals he can't understand why comedy icons including Rivers and Mason have decided to change their face because they never relied on their looks to make a living.
He tells Britain's Esquire magazine, "I've always, always hated the way I look. But that's OK, I'm a comedian, it wouldn't be good for me to be vain. If I was worried about the way I look - I'm 41 - it's a slippery slope to fillers and Botox and looking for lines on my forehead and all that kind of nonsense.
"It's ridiculous. I can't believe it when I look at Jackie Mason and Joan Rivers, two of the great American comedians, their faces don't move. How do you sell a joke in the way you would have done before? Because now you've got a mask.
"Especially Jackie Mason, you think, 'No one thought you were handsome! Everyone thought you were funny. What are you holding on to?'"