Mac Barnett

Mac Barnett is the author of several picture books, including BILLY TWITTERS AND HIS BLUE WHALE PROBLEM, GUESS AGAIN!, and OH NO! (OR HOW MY SCIENCE PROJECT DESTROYED THE WORLD). He also writes the Brixton Brothers series of mysteries. Mac is the founder of the Echo Park Time Travel Mart, a convenience store for time travelers, and serves on the board of 826LA, a nonprofit writing and tutoring center.

From the dust jacket of Extra Yarn