The Grinch is a fictional character created by Dr. Seuss that spent 53 years living on a cliff, overlooking the town of Whoville and its residents The Whos.
The Grinch hates the Christmas season, making particular note of how disturbing the various noises of Christmas time.
With the help of his dog Max, he dresses as Santa Clause breaks into the Whos' homes to steal everything they own and dump it off a nearby mountain.
In the end the Grinch realizes that the holiday has a deeper meaning that he never considered.
He stops the Whos' belongings from falling off the edge of the mountain, and in the process his heart grows three sizes.