You're correct! The 1966 animated television special "How the Grinch Stole Christmas" was the first adaptation of the Dr. Seuss book of the same name. The story follows the grumpy Grinch, who plans to ruin Christmas by stealing all the presents and decorations from the Whos in Whoville. With his loyal dog Max, the Grinch sets out on Christmas Eve to steal the Christmas spirit from the unsuspecting Whos. The special was directed by Chuck Jones and narrated by Boris Karloff.