Bill Maher Compares Donald Trump to an Orangutan on 'Tonight Show' (Video)

Janet Van Ham/HBO

Bill Maher says he tried for years to book Donald Trump on his talk show, but he's glad it never panned out.

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"I asked for years, and he always lied and said, 'Oh I'll be there,' and he never showed up," Maher told Jay Leno on Monday's The Tonight Show. "And I'm glad he didn't because, you know, he turned out to be, first of all, a terrible racist."

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Maher said Trump has been tweeting "mean things" about him but that he's not looking for a feud with the outspoken Celebrity Apprentice host.

"I certainly only wish the best for the syphilitic monkey who does his Twitter feed," he joked.

He explained that "what got [Trump] so mad was, we did a new rule one week that, supposed, perhaps Donald Trump had been the spawn of his mother having sex with orangutan," he said, adding: "The color of his hair and the color of an orange orangutan is only two things in nature of the same color."

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Bringing up Trump's widely ridiculed offer to President Obama to show proof of his U.S. citizenship, Maher joked that he's willing to offer $5 million to Trump to donate the charity of his choice -- the Hair Club for Men, the "Institute for Incorrigible Douchebaggery" -- if the real estate mogul offers proof that he's not the son of a monkey.

Watch the segment below.