Karen and Charlotte Pence, the wife and daughter of US vice president Mike Pence, released a children’s book today, Marlon Bundo’s Day in the Life of the Vice President, about their family’s pet rabbit. But that’s not the only book about Marlon Bundo to go on sale this week.

John Oliver, host of the HBO late-night show Last Week Tonight, capped a lengthy diatribe against the vice president (focused mainly on Pence’s views on gay people) with news of a competing book, A Day in the Life of Marlon Bundo. It, too, is about the Pence family rabbit—only this book tells the story of how Bundo falls in love with another male bunny, Wesley, while playing in the garden of the grounds of the US Naval Observatory, where the real-life Pences and Bundo live. It’s an explicit response to Pence’s record on LGBTQ rights.

Oliver’s storybook was written by show writer Jill Twiss, with illustrations by EG Keller, and published by Chronicle Books. The audiobook is read by actor Jim Parsons of The Big Bang Theory. The Pences’ book was published by Regnery Kids.

“It’s unfortunate that ​anyone would feel the need to ​ridicule an educational children’s book and turn it into something controversial and partisan,” Regnery writes in an emailed statement.

The parody’s antagonist, Stink Bug, is an anti-gay marriage politician with a strong resemblance to Pence.

Oliver says he is donating all the proceeds of the book to the Trevor Project, a suicide hotline for young LGBTQ people, and the AIDS charity AIDS United. The stunt, one of many goofy pranks launched on the show, is already working: His book is currently sitting at the top of Amazon’s overall bestselling books list, which is updated hourly.

The reviews on Amazon suggest the book is also succeeding as a campaign against Pence and his family. At the time of this writing, there are 739 reviews for Oliver’s book and they’re overwhelmingly positive—but only a quarter are marked as genuine purchases of the book, suggesting that people who haven’t read the book are coming to the page to shower it with good ratings. Meanwhile, over on the Amazon page for the Pence family’s book, there’s a pretty clear campaign to bring down the ratings of the book. The Pence book currently has just 27 reviews, only one of which is from someone who made a verified purchase. It’s also the only customer review which is positive.

Other one-star reviews currently on the page are clearly from Oliver fans:

Screenshot by Quartz

But now it’s only possible to leave a review for Pence’s book with a verified purchase, which likely means that Amazon detected a brigade of trolls at some point today and switched the page over to accept reviews only from verified purchasers. We’ve reached out to Amazon to confirm whether this was the case.