William Henry Green II, known as Hank Green, is an American YouTuber, science communicator, novelist, and entrepreneur. He produces the YouTube channel Vlogbrothers with his brother John Green and hosts the educational YouTube channels Crash Course and SciShow. He has amassed a large social media following and has been involved in social activism and charity initiatives, including the Project for Awesome and the Awesome Socks Club, which has donated over $3 million to charity.