Which animator is recognized for co-authoring "The Illusion of Life" with Frank Thomas?

The correct answer is based on the significant contributions of Ollie Johnston to the field of animation, particularly in collaboration with Frank Thomas. Johnston, along with Thomas, was a key figure in the development of Disney's animation style and techniques. Their book, "The Illusion of Life: Disney Animation," published in 1981, is a seminal work that delves into the principles of animation and storytelling that defined Disney's approach.

In this book, they introduced the twelve principles of animation, which have become foundational knowledge for animators worldwide. Their partnership not only exemplifies a deep understanding of animation artistry but also serves as a crucial educational resource for aspiring animators.

While the other animators listed—Ward Kimball, Marc Davis, and Milt Kahl—were all influential figures at Disney and contributed to the animation industry, it was Johnston's specific collaboration with Thomas that produced this landmark book. Each of these individuals had their unique style and impact, but the co-authorship of "The Illusion of Life" distinctly pairs Frank Thomas with Ollie Johnston, making this collaboration particularly noteworthy in the history of animation.