Credit: TBS

Barack Obama saved his scariest Halloween story for Samantha Bee. During Monday’s episode of Full Frontal with Samantha Bee, the President of the United States was asked by the show’s host to relay a “spooky story about what happens if people don’t vote.”

“Donald Trump could be president,” Obama said in response.

Obama appeared on the TBS late-night show in an effort to speak to millennial voters about next week’s presidential election battle between Trump and Democratic opponent Hillary Clinton.

“The reason I’m here is not just to celebrate Halloween with you, but it is actually because I want to let first time voters know why it is so important to vote,” Obama said to Bee. “This is probably the most important election of our lifetimes. The choices could not be clearer. And if we want to build on progress on issues like climate change and gender equality and making sure everybody has health care and making sure young people have a good education and can afford college, they’ve got to make sure their voices are heard.”

Of millennials, Obama added, “young people are more interested and engaged than we give them credit for. Sometimes they get cynical. Hard to believe watching this campaign.”

During his interview with Bee, the president also revealed his daughter Malia had voted for the first time this year. “The pride she took in casting her ballot is the pride I think a lot of young people feel, but you have to talk to them about the things they care about,” Obama said.

In addition to talking about the impact millennials might have on the election, Bee also asked Obama what critics of Clinton will say to delegitimize her presidency, if she were to get elected next week.

“She’s tired, she’s moody, she’s being emotional,” Obama said. “When men are ambitious it’s just taken for granted — well of course they’re ambitious. When women are ambitious — why? That theme, I think, will continue throughout her presidency and it’s contributed to this notion that she’s hiding something.”

As for Trump, Bee wondered if Obama had thought of “whispering in Donald Trump’s ear, ‘You were right, I wasn’t born here'” to mess with the GOP nominee, who was a key figure in the birther movement against the president.

“I think it’s fair to say that I will be organizing my post-presidency where I’m not close enough to him to whisper in his ear,” Obama said.

Watch the interview below.