The other, “Last Week Tonight With John Oliver Presents a Day in the Life of Marlon Bundo,” is a gay romance between two bunnies that was the brainchild of the HBO comedy host John Oliver.

So far, that is the more popular of the two.

Mr. Oliver revealed the book, which was written by Jill Twiss and credits the titular bunny as a co-author, on his weekly late-night show on Sunday. He described it as a mocking rebuke of the vice president’s longtime opposition to gay and transgender rights.

“Please buy it for your children, buy it for any child you know or buy it because you know it would annoy Mike Pence,” Mr. Oliver told his viewers. Parody aside, he assured them, “This is a real book for children.”

And buy it they have. By Tuesday the book, which beat Ms. Pence’s to Amazon by two days, had risen to the No. 1 spot on the website’s best-seller list, knocking pre-ordered copies of the upcoming memoir by James Comey down to No. 2.

Ms. Pence’s book on Marlon Bundo had reached No. 4 on the list by late afternoon.

Mr. Comey’s book, “A Higher Loyalty: Truth, Lies, and Leadership,” has been highly anticipated for potential insights it could provide into the tumultuous Trump White House and Mr. Comey’s abrupt dismissal as director of the F.B.I. last year.