Rosie O'Donnell calls Donald Trump 'mentally unstable' and 'a criminal' in series of tweets

Rosie O'Donnell reignited her long-running feud with Donald Trump on Twitter over the weekend, posting a series of tweets, many of which were written in all caps, lashing out at him and calling for "resistance" to the president-elect.

On Dec. 31, she tweeted a link to a Huffington Post article about emails that revealed that the head of the U.S. Office of Government Ethics personally ordered a number of tweets praising Trump's announcement that he planned to sever ties to his businesses to avoid conflicts of interest.

"We told your counsel that we'd sing your praises if you divested and we meant it!" one of the tweets read. O'Donnell tweeted with the link, "Donald Trump is a sick man."

She went on to call him, "mentally unstable," and warning, "less than three weeks to stop him, America," along with a link to a CNN story in which the author of a decades-old biography critical of Trump claimed the president-elect had him kicked off of his golf course.

She also posted "DT is mentally ill" along with a Buzzfeed post on a photo series showing Trump's quotes about women written on models' bodies.

And she accompanied a link to an MSNBC column about Trump taking "credit for others' work," like bringing back jobs, with the assertion, "Trump is a criminal."

She responded to another Twitter user who wondered, "how is he allowed to take the office," by saying that time would be "the moment democracy dies" and told two other Twitter users, "He is the cheapest billionaire ever. He is a fake and a fraud. He earned nothing. Daddy's money not his."

She retweeted a number of other users who criticized the president-elect, including one with a gif of Trump as Vladimir Putin's puppet and another with a link to a Change.org petition, which claimed it was created by a nurse with psychiatric experience, calling for Trump to be involuntarily committed.

She also posted a photo of what appeared to be a large ad for a Trump building in India above what looked like poor conditions, captioning it simply, "2017."

Late in the evening on Jan. 1, she retweeted another user's tweet linking to another Huffington Post article, this time titled in part, "15 Examples of Donald Trump Being Racist." O'Donnell added, "the world's worst human"

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O'Donnell's Twitter bio reads, "2017 - TIME TO YELL."

It's unclear what prompted O'Donnell's series of tweets but one of her first tweets was to Trump himself in response to his New Year's Eve tweet, wishing a happy 2017 to all, even his "many enemies."

The comedian and Trump have a long-running feud that began when she criticized his handling of a scandal involving then-Miss USA Tara Conner, mocking Trump on ABC's The View and calling him "a snake-oil salesman."

Since then, Trump has called her "fat" and a "real loser" and leveled other insults at her on Twitter, TV and during the 2016 presidential campaign, saying during the first presidential debate against Hillary Clinton, " I think everybody would agree that [O'Donnell] deserves it and nobody feels sorry for her."

While O'Donnell remained mostly silent about Trump's candidacy during the Republican presidential primary, she posted a few tweets about her nemesis leading up to the election. She even had a highly-publicized chat with Ivanka Trump after the two women ran into each other in New York last fall.

Representatives for the president-elect have yet to respond to The Hollywood Reporter's request for comment.

Read some of O'Donnell's weekend tweets below.