John Oliver is finally taking on Donald Trump -- and the “Last Week Tonight” host is not mincing words.

“At this point, Donald Trump is America’s back mole,” Oliver said on Sunday’s episode. “It may have seemed harmless a year ago, but now that it’s become frighteningly bigger, it’s no longer wise to ignore it.”

Oliver, who has largely avoided discussing Trump on his show, was unequivocal in his criticism of the Republican frontrunner.

Trump is a “bullshit artist,” Oliver said, and “a litigious serial liar with a string of broken business ventures and the support of a former Klan leader.”

Over the course of about 20 minutes, Oliver systematically dismantled Trump’s “successful” and “tough” image, and urged voters to think deeply about the billionaire's policies rather than focusing on his “brand.”

“A candidate for president needs a coherent set of policies. Whatever you think about Marco Rubio and Ted Cruz, at least you basically know where they stand, but Trump’s opinions have been wildly inconsistent,” said Oliver. “He’s been pro choice and pro life; he’s been for and against assault weapon bans; in favor of both bringing in Syrian refugees and deporting them out of the country.”

What’s frightening, Oliver added, is that “we have no way of knowing which of [Trump’s] inconsistent views he will hold in office … Will he stand by his statement that vaccines are linked to autism or his belief that Mexico is sending us rapists?” Or will he implement his plan to defeat ISIS by killing families of terrorists?

In order to help voters separate the man from the brand, Oliver announced a new campaign to “uncouple the magical word [‘Trump’] from the man he really is.” And it seems Oliver didn't have to dig very deep to find a way to do this.

According to journalist Gwenda Blair in her book “The Trumps: Three Generations That Built An Empire,” Trump's family name was actually changed at one point from the significantly less impressive-sounding last name “Drumpf.”

“Fucking Drumpf!” Oliver exclaimed with delight. “Drumpf is much less magical. It’s the sound produced when a morbidly obese pigeon flies into the window of a foreclosed Old Navy. Drumpf: It’s the sound of a bottle of store-brand root beer falling off the shelf in a gas station minimart.”

Oliver told the audience that the show had filed paperwork to trademark the name “Drumpf” and purchased the domain DonaldJDrumpf.com, where netizens can buy a special “Make Donald Drumpf Again” hat. Visitors can even download a Google Chrome extension that will replace the word “Trump” with “Drumpf” whenever it appeared in your browser.

Visit https://t.co/lGqmpDEDFX to download the Drumpfinator Chrome Extension and change every "Trump" in your browser to "Drumpf." — Last Week Tonight (@LastWeekTonight) February 29, 2016

Oliver also asked viewers to help #MakeDonaldDrumpfAgain -- a plea that was quickly answered by social media users.

Tonight's @LastWeekTonight piece on Trump should be required viewing for...well, everyone. #MakeDonaldDrumpfAgain — Joe Henderson (@Henderson_Joe) February 29, 2016

I've never seen John Oliver angrier than he was talking about Trump tonight @LastWeekTonight. #MakeDonaldDrumpfAgain https://t.co/SsmSlXKLI7 — Jim Reedy (@jim_reedy) February 29, 2016

Winner of the night: JOHN OLIVER. Go watch his Trump segment right now. Incredible. @LastWeekTonight #makedonalddrumpfagain — Matty Sumida (@mattysumida) February 29, 2016

Drumpf - An overpriced instrument that produces a stale noise yet still gathers an audience. Also see "windbag". #MakeDonaldDrumpfAgain — Mattastrophe (@smokingmocha) February 29, 2016

That was the best deconstruction so far of the psychology behind a naked emperor mythologized. @LastWeekTonight #MakeDonaldDrumpfAgain — Cameron Leahy (@cameronleahy) February 29, 2016

“If you are thinking of voting for Donald Trump, the charismatic guy promising to ‘Make America Great Again,’ stop and take a moment to imagine how you would feel if you just met a guy named Donald Drumpf,” said Oliver. “Would you think he would make a good president or is the spell now somewhat broken?”