The Democratic field of candidates is full to bursting — and so is the list of targets for President Donald Trump.

Here's what Trump has had to say so far about his would-be challengers.

Joe Biden

Former Vice president Joe Biden speaks at the International Association of Fire Fighters legislative conference in Washington on March 12, 2019. Win McNamee / Getty Images file

Within hours of Joe Biden's announcement, Trump dubbed the 76-year-old former vice president “Sleepy Joe,” and called him someone whose "intelligence" had been "long in doubt."

Weeks later, Trump amended the nickname ever so slightly, dubbing Biden "SleepyCreepy Joe."

Welcome to the race Sleepy Joe. I only hope you have the intelligence, long in doubt, to wage a successful primary campaign. It will be nasty - you will be dealing with people who truly have some very sick & demented ideas. But if you make it, I will see you at the Starting Gate! — Donald J. Trump (@realDonaldTrump) April 25, 2019

Looks to me like it’s going to be SleepyCreepy Joe over Crazy Bernie. Everyone else is fading fast! — Donald J. Trump (@realDonaldTrump) May 10, 2019

In March, Trump insulted Biden as “another low I.Q. individual” after the former Delaware senator accidentally admitted he was going to run for president, and then corrected himself.

Joe Biden got tongue tied over the weekend when he was unable to properly deliver a very simple line about his decision to run for President. Get used to it, another low I.Q. individual! — Donald J. Trump (@realDonaldTrump) March 18, 2019

Trump, in March 2018, had previously ripped Biden as “Crazy Joe,” tweeting that he was “trying to act like a tough guy” but was “weak, both mentally and physically.” The slap-back came after Biden, at a rally at the University of Miami attended by a sexual assault awareness advocacy group, said he would "beat the hell out of" Trump if they had been in high school together and if he heard him demeaning women.

Trump, in his tweet, said that, if they fought, Biden “would go down fast and hard, crying all the way.”

Crazy Joe Biden is trying to act like a tough guy. Actually, he is weak, both mentally and physically, and yet he threatens me, for the second time, with physical assault. He doesn’t know me, but he would go down fast and hard, crying all the way. Don’t threaten people Joe! — Donald J. Trump (@realDonaldTrump) March 22, 2018

Trump has also previously dubbed Biden as “1 percent Joe” — a critical reference to his poor showing during his bid for the 2008 Democratic presidential nomination.

Bernie Sanders

Sen. Bernie Sanders, I-VT, at a press conference at the Capitol on March 28, 2019. Drew Angerer / Getty Images file

Trump debuted his "Crazy Bernie" jibe against Sanders during the 2016 Democratic primary, as the independent Vermont senator racked up a series of primary wins against eventual nominee Hillary Clinton.

I don't want to hit Crazy Bernie Sanders too hard yet because I love watching what he is doing to Crooked Hillary. His time will come! — Donald J. Trump (@realDonaldTrump) May 11, 2016

Big wins in West Virginia and Nebraska. Get ready for November - Crooked Hillary, who is looking very bad against Crazy Bernie, will lose! — Donald J. Trump (@realDonaldTrump) May 11, 2016

Trump has since reprised the insult as the 2020 Democratic race has kicked into gear, tweeting his prediction earlier this month that the contest would come down to "Crazy Bernie Sanders vs. Sleepy Joe Biden."

I believe it will be Crazy Bernie Sanders vs. Sleepy Joe Biden as the two finalists to run against maybe the best Economy in the history of our Country (and MANY other great things)! I look forward to facing whoever it may be. May God Rest Their Soul! — Donald J. Trump (@realDonaldTrump) April 17, 2019

Sanders has hit back by saying, "What's crazy is that we have a president who is a racist, a sexist, a xenophobe and a fraud."

What’s crazy is that we have a president who is a racist, a sexist, a xenophobe and a fraud. We are going to bring people together and not only defeat Trump but transform the economic and political life of this country. Say you're in: https://t.co/rxqbjJJKv3 https://t.co/HoJG0Rlwq1 — Bernie Sanders (@BernieSanders) February 20, 2019

Elizabeth Warren

Sen. Elizabeth Warren, D-Mass., speaks at the "We The People" Summit in Washington on April 1, 2019. Brendan Smialowski / AFP - Getty Images file

Trump has repeatedly used the slur "Pocahontas" against Warren, dating back the 2016 presidential race, when the Massachusetts senator emerged as a fierce critic of Trump. The insult references her past claims on Native American heritage, though she was never enrolled as a member of a tribe.

He also slammed her as “goofy Elizabeth Warren” during the 2016 campaign, but revived the slur after Warren announced her 2020 bid.

@elizabethforma Goofy Elizabeth Warren, sometimes referred to as Pocahontas because she faked the fact she is native American, is a lowlife! — Donald J. Trump (@realDonaldTrump) May 25, 2016

Today Elizabeth Warren, sometimes referred to by me as Pocahontas, joined the race for President. Will she run as our first Native American presidential candidate, or has she decided that after 32 years, this is not playing so well anymore? See you on the campaign TRAIL, Liz! — Donald J. Trump (@realDonaldTrump) February 9, 2019

Beto O'Rourke

Beto O'Rourke speaks at the "We The People" summit in Washington on April 1, 2019. Brendan Smialowski / AFP - Getty Images file

Trump took aim at O'Rourke in March, just days after his formal campaign launch, ragging on the former Texas congressman’s penchant for moving his hands and arms around when he talks.

"I think he's got a lot of hand movement. I've never seen so much hand movement,” Trump said during a White House event. “I said, 'Is he crazy or is that just the way he acts?'"

"I watched him a little while this morning, during I assume it was some kind of a news conference, and I’ve actually never seen anything quite like it,” Trump said.

Earlier, during an October campaign event for Sen. Ted Cruz (who was facing a tough challenge from O'Rourke), Trump called the candidate a "stone-cold phony named Robert Francis O'Rourke, sometimes referred to as 'Beto.'" O'Rourke's given name is "Robert Francis." Beto" is a nickname he has used since childhood.

Trump also slammed O'Rourke as "a flake" in a tweet he wrote after a debate between O'Rourke and Cruz.

Watched the debate last night & Beto O’Rourke, who wants higher taxes and far more regulations, is not in the same league with Ted Cruz & what the great people of Texas stand for & want. Ted is strong on Crime, Border & 2nd A, loves our Military, Vets, Low Taxes. Beto is a Flake! — Donald J. Trump (@realDonaldTrump) October 17, 2018

Amy Klobuchar

Sen. Amy Klobuchar, D-Minn., announces her candidacy for president in Minneapolis on Feb. 10, 2019. Kerem Yecel / AFP - Getty Images file

Trump went relatively easy on the Minnesota senator, merely taking aim at how the snowy weather conditions affected her February campaign launch.

“By the end of her speech she looked like a Snowman(woman)!” he tweeted, mocking Klobuchar for “talking proudly of fighting global warming while standing in a virtual blizzard of snow, ice and freezing temperatures”

Well, it happened again. Amy Klobuchar announced that she is running for President, talking proudly of fighting global warming while standing in a virtual blizzard of snow, ice and freezing temperatures. Bad timing. By the end of her speech she looked like a Snowman(woman)! — Donald J. Trump (@realDonaldTrump) February 10, 2019

Kirsten Gillibrand

Sen. Kirsten Gillibrand, D-NY, speaks to guests at a campaign event in Des Moines, Iowa, on April 17, 2019. Scott Olson / Getty Images file

Trump appears to have stayed away from Gillibrand since she announced her campaign earlier this year. But in 2017, he landed a harsh blow against her on Twitter that many said was sexually suggestive.

Trump, on Twitter, slammed Gillibrand as a "Lightweight Senator," a "total flunky for Chuck Schumer" and said she was “someone who would come to my office ‘begging’ for campaign contributions not so long ago.

Gillibrand, Trump added, “would do anything for them.”

Lightweight Senator Kirsten Gillibrand, a total flunky for Chuck Schumer and someone who would come to my office “begging” for campaign contributions not so long ago (and would do anything for them), is now in the ring fighting against Trump. Very disloyal to Bill & Crooked-USED! — Donald J. Trump (@realDonaldTrump) December 12, 2017

The tweet came amid the backdrop of the burgeoning #MeToo movement and after Gillibrand called on Trump to resign due to the multiple allegations of sexual misconduct made against him, allegations the president has vehemently denied.

Cory Booker

Sen. Cory Booker, D-NJ, takes a selfie with supporters during his campaign kickoff event in Newark on April 13, 2019. Andres Kudacki / AP file

Trump has largely handed Booker a pass since the New Jersey senator launched his campaign, but he had attacked him repeatedly prior to his 2020 bid.

In July 2016, following Booker’s speech at the Democratic National Convention — during which the senator took shots at the then-GOP-nominee — Trump tweeted a cryptic critical message that left pundits scratching their heads.

“I know more about Cory than he knows about himself,” Trump tweeted.

If Cory Booker is the future of the Democratic Party, they have no future! I know more about Cory than he knows about himself. — Donald J. Trump (@realDonaldTrump) July 26, 2016

Then, last year, amid a bitter confirmation battle for Supreme Court nominee Brett Kavanaugh, Trump again took aim at Booker, who is a member of the Senate Judiciary Committee.

"Take a look at Cory Booker," Trump said during an October White House press conference. "He ran Newark, New Jersey, into the ground. He was a horrible mayor; and he made statements that when he was in high school or college what he was doing. He actually made the statements. And now he's talking about Judge Kavanaugh."

His comments appeared to reference a 1992 article Booker for a student newspaper when he was an undergraduate at Stanford University in which he wrote about a time in high school he attempted to grope a girl.

Kamala Harris

Sen. Kamala Harris, D-Calif., speaks during the "She The People" forum in Houston on April 24, 2019. Sergio Flores / Getty Images

Trump took a different approach with the California senator, paying her a modest compliment during an interview with The New York Times published in February.

When asked at that time who he felt was the Democratic Party’s “toughest candidate” in the race, he said it was Harris.

“I would say, the best opening so far would be Kamala Harris,” he said, although the Times’ transcript of the interview noted that he mispronounced her name. “I would say, in terms of the opening act, I would say, would be her.”

“I just think she seemed to have a little better opening act than others,” Trump said.

But in May, Trump finally dissed Harris, calling her "very nasty" in an interview with Fox Business.

The White House has also been critical of the California senator. In July 2018, the official White House Twitter account attacked her on illegal immigration, claiming she “supporting the animals of MS-13.”

.@SenKamalaHarris, why are you supporting the animals of MS-13? You must not know what ICE really does. Here is a link to help you out: https://t.co/kcrNj4aVMU — The White House (@WhiteHouse) July 2, 2018

Pete Buttigieg

Trump, in May, finally, devised a nickname — "Alfred E. Neuman" — for the upstart 37-year-old mayor of South Bend, Ind., whose presidential candidacy had attracted significant media attention.

"Alfred E. Neuman cannot become president of the United States," Trump told Politico in an interview about Buttigieg.

Neuman is the fictional cover-boy for Mad magazine, the 67-year-old humor publication, who is known for his big ears, gap-toothed smile and "What, Me Worry" catchphrase.

Buttigieg, who has been a fierce critic of Trump on the campaign trail, told reporters after the interview was published that he "had to Google that" and that he "didn't get the reference."

Bill de Blasio

Trump waited about three hours after Bill de Blasio officially announced his presidential run to insult the New York City mayor on Twitter.

De Blasio, Trump tweeted, is "the worst mayor in the U.S." and "a joke," adding that "NYC HATES HIM!"

The Dems are getting another beauty to join their group. Bill de Blasio of NYC, considered the worst mayor in the U.S., will supposedly be making an announcement for president today. He is a JOKE, but if you like high taxes & crime, he’s your man. NYC HATES HIM! — Donald J. Trump (@realDonaldTrump) May 16, 2019

On the other hand, there are several Democratic candidates Trump hasn't appeared to comment on — yet.

They include former Colorado Gov. John Hickenlooper, Washington Gov. Jay Inslee, Massachusetts Rep. Seth Moulton, California Rep. Eric Swalwell, Ohio Rep. Tim Ryan, former Maryland Rep. John Delaney, former Housing and Urban Development Secretary Julián Castro and Hawaii Rep. Tulsi Gabbard.

He also hasn't lobbed anything at entrepreneur Andrew Yang, author Marianne Williamson or Miramar, Fla., Mayor Wayne Messam, who are all also running for president.