The Grinch is a fictional character created by author Dr. Seuss in his children's book "How the Grinch Stole Christmas!" The Grinch is a mean, green creature who lives in a cave above the town of Whoville, and he hates Christmas with a passion. He decides to steal Christmas from the Whos by dressing up as Santa Claus and taking all their presents and decorations. However, he ultimately learns the true meaning of Christmas and becomes a better person.