The ghostwriter of Donald Trump’s 1987 memoir, The Art of the Deal, has expressed regrets about his work on behalf of the 2016 Republican presidential nominee.

In the late 1980s, Tony Schwartz was approached by Trump to write the autobiography, for which Trump had already secured a contract with Random House. Motivated by financial fears, Schwartz agreed to write the book if he could share in half of Trump’s half-a-million-dollar advance and half the book’s royalties, he told The New Yorker.

But despite following Trump for eighteen months, beginning in late 1985, Schwartz found Trump an unlikeable character—and thus difficult to portray somewhat sympathetically. In the end, the memoir became a kind of fictional nonfiction work, written to “play to people’s fantasies.”

Ultimately, “I put lipstick on a pig,” he told the New Yorker. “I feel a deep sense of remorse that I contributed to presenting Trump in a way that brought him wider attention and made him more appealing than he is.” He adds: “I genuinely believe that if Trump wins and gets the nuclear codes, there is an excellent possibility that it will lead to the end of civilization.”

Edward Kosner, the former editor and publisher of New York, agreed and told the New Yorker, “Tony created Trump. He’s Dr. Frankenstein.”

Read the full story at The New Yorker.

Related viewing: Funny or Die’s movie adaptation of The Art of the Deal.