Tonight Show With Jimmy Fallon December 13, 2019 4:44 am ‘Tonight': Trump Goes After Greta Thunberg In his monologue, Jimmy Fallon jokes about President Donald Trump going after 16-year-old climate activist Greta Thunberg, SantaCon and the latest impeachment hearings. US & World Videos 1:07 Britney Spears spotted as authorities respond to alleged hotel incident 2:15 Prince William and Kate Middleton ‘going through hell,' friend claims (report) 8:01 Lady Gaga's outfit changes, Rihanna's bold looks and more iconic Met Gala moments 1:59 TikTok's Maddy Baloy dead at 26: Gordon Ramsay and Tay Lautner pay tribute 3:04 Progress being made on demolition of overpass on I-95 in Norwalk