President Donald Trump mocked teenage global warming activist Greta Thunberg on Thursday after getting TIME’s Person of the Year cover.

“So ridiculous,” Trump wrote, sharing the news on Twitter. “Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill!”

So ridiculous. Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill! https://t.co/M8ZtS8okzE — Donald J. Trump (@realDonaldTrump) December 12, 2019

Trump’s comment drew instant criticism from global warming activists and critics on Twitter who have touted Thunberg as an untouchable heroine.

In response to Trump, Thunberg changed her Twitter bio:

Donald Trump Jr. also ripped TIME magazine’s choice on Twitter.

“Time leaves out the Hong Kong protesters fighting for their lives and freedoms to push a teen being used as a marketing gimmick,” he wrote. “How dare you?”

Time leaves out the Hong Kong Protesters fighting for their lives and freedoms to push a teen being used as a marketing gimmick. How dare you? https://t.co/dnV9mESM6G — Donald Trump Jr. (@DonaldJTrumpJr) December 11, 2019

President Trump also mocked Thunberg in September after she spoke angrily to the United Nations for failing to address climate change.

“She seems like a very happy young girl looking forward to a bright and wonderful future,” he wrote. “So nice to see!”