David Letterman has kept a relatively low profile since he walked away from late night TV back in 2015.
But the legendary comedian and former talk show host has poked his head out of retirement to blast President Donald Trump - and what a blast it is.
Speaking to Vulture, the 69-year-old said he's known Trump since the 1980s and interviewed him on a number of occasions on Late Show with David Letterman.
"He was a joke of a wealthy guy," Letterman said.
"We didn't take him seriously. He'd sit down, and I would just start making fun of him. He never had any retort. He was big and doughy, and you could beat him up. He seemed to have a good time, and the audience loved it, and that was Donald Trump," he said.
"Beyond that, I remember a friend in the PR business told me that he knew for a fact - this was three or four presidential campaigns ago - that Donald Trump would never run for president; he was just monkeying around for the publicity. So I assumed that was the story and now it turns out he's the President."
In the interview, Letterman encouraged the media to stop focusing so much on Trump's outrageous statements, saying: "We gotta stop that and instead figure out ways to protect ourselves from him. We know he's crazy. We gotta take care of ourselves here now."
Instead, Letterman wants the media to keep the pressure on Trump by exploiting his weaknesses, such as his "thin skin".
"In a 2007 playoff game, a swarm of midges from Lake Erie caused Yankees reliever Joba Chamberlain to blow the game with a few wild pitches. baseball game in Cleveland, and a swarm of flies came on the field and the batters were doing this [mimes swatting at flies] while the pitcher was throwing 100 miles an hour," Letterman said.
"Well, that's Alec Baldwin and Saturday Night Live. It's distracting the batter. Eventually Trump's going to take a fastball off the sternum and have to leave the game."
One of Letterman's most memorable interactions with Trump on The Late Show with David Letterman was back in 2012.
Appearing on the show to promote his range of ties, Trump touched on China and said the country was "ripping our heart out".
Letterman then revealed on air that Trump's ties were actually manufactured in China, leaving the billionaire almost speechless:
And humiliating Donald Trump in an interview is exactly what he'd be doing if he was still on TV, Letterman said.
"I would just start with a list," Letterman said about a hypothetical interview with Trump.
"'You did this. You did that. Don't you feel stupid for having done that, Don? And who's this goon Steve Bannon, and why do you want a white supremacist as one of your advisers? Come on, Don, we both know you're lying. Now, stop it.'
"I think I would be in the position to give him a bit of a scolding and he would have to sit there and take it.