On Dec. 18, 2020, the U.S. Court of Appeals for the Ninth held in Dr. Seuss Enterprises, L.P. v. ComicMix, 2020 WL 7416324 (ComicMix), that ComicMix's illustrated book combining elements of several Dr. Seuss children's books with characters, themes and other features of the popular sci-fi series Star Trek was not a fair use of the Seuss material from which it had admittedly been "slavishly" copied. The Ninth Circuit therefore reversed and remanded the district court's determination of fair use and grant of summary judgment to ComicMix. (See our May 24, 2019 column, "'Mash-Up' of Dr. Seuss and Star Trek Held Fair Use," discussing the district court decision.) The Ninth Circuit found that all four fair use factors set forth in §107 of the Copyright Act favored plaintiff. In particular, the Ninth Circuit found that ComicMix's use was not transformative and would cause significant market harm to plaintiff. On the claim of trademark infringement (which is beyond the scope of this column), the Ninth Circuit affirmed the grant of summary judgment to ComicMix.