(CNN) John Oliver's parody book about Vice President Mike Pence's family pet has sold out.

The "Last Week Tonight" host appeared on "Ellen" on Tuesday to talk about his new children's book, "Last Week Tonight with John Oliver Presents a Day in the Life of Marlon Bundo." The book, which Oliver is using to troll Pence, coincides with the Pence family's release of their own children's book about the family pet rabbit, Marlon Bundo.

Oliver's book, released on Sunday, a day before the Pence family released their book, is described as a "picture book about a Very Special boy bunny who falls in love with another boy bunny."

Oliver told Ellen DeGeneres that the inspiration for his book stemmed from the release of the Pences' book, saying the "family has written a book about their bunny, so we on top of that have released our own book about his bunny where his bunny falls in love with another male bunny."

Oliver's book is the No. 1 best-seller on Amazon.com as of Tuesday, which came as a surprise even to the author.

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