High Quality Content by WIKIPEDIA articles! Horton Hears a Who!, also known as Dr. Seuss` Horton Hears a Who!, is a 2008 American CGI-animated comedy feature film based on the Dr. Seuss book of the same name. It is the fourth feature film from Blue Sky Studios, and the third feature film based on a Dr. Seuss book, following How the Grinch Stole Christmas and The Cat in the Hat. It is the second most successful feature film based on Dr. Seuss, following How the Grinch Stole Christmas, and it is also the first Dr. Seuss adaptation fully animated using CGI technology.