That's a good one.
4 seconds sound clip from the How the Grinch Stole Christmas (2000) movie soundboard.
You can hear this line at 00:41:29 in the Blu-ray version of the movie.
Quote context
[...]
- Mr. Grinch, I came to invite you to be Holiday Cheermeister.
- 'Holiday Whoobie-what-y?' -Cheermeister.
- 'Cheermeister... Celebrate with friends.'
- I know you hate Christmas, but what if it's all just a misunderstanding?
- I mean, I myself am having some Yuletide doubts.
- But maybe if you can reunite with the Whos, and be a part of Christmas...
- Grow up!
[...]