Kurzgesagt is a German animation studio founded by Philipp Dettmer. The studio’s YouTube channel focuses on minimalist animated educational content, using the flat design style. It discusses scientific, technological, political, philosophical and psychological subjects.
Math Textbook with Cat Pictures
Sheldon Axler is a funny math professor and he put his cats' pictures into his math textbook, Precalculus: A Prelude to Calculus.