Sour Kangaroo, also known as Jane Kangaroo, is the (former) main antagonist of the 1954 children's book, Horton Hears A Who!, by Dr Seuss, the 1970 animated television special, Horton Hears A Who!, the 1992 animated film I Can Hear You, the 2000 Broadway musical, Seussical, and Blue Sky's 4th animated feature film, Dr. Seuss's Horton Hears a Who!. She also appears in the Horton Hears A Who! story in the 1996 live action/puppet TV series, The Wubbulous World of Dr. Seuss.