Narrator: "Pooh-pooh to the Whos" he was grinchily humming.
The Grinch: They're finding out now that no Christmas is coming. They're just waking up, I know just what they'll do. Their mouths will hang open a minute or two. Then the Whos down in Whoville will all cry "booo-hooo."
At the end when the sled full of Christmas stuff is on the mountaintop, it starts sliding off the edge. It's going fast enough that it should be long gone by the time the Grinch reaches it, but when he does it's still right near the top of the mountain.
The iconic song, "You're a Mean One, Mr. Grinch" was sung by Thurl Ravenscroft. Mr. Ravenscroft (who died in 2005 at 91 years old) is also famous for providing the deep, resonant voice of Tony the Tiger, the brand mascot for Kellogg's Frosted Flakes.