That is so, I've heard it said.
5 seconds sound clip from the The Nightmare Before Christmas (1993) movie soundboard.
You can hear this line at 00:23:53 in the Blu-ray version of the movie.
Quote context
[...]
- For the ruler of this Christmas Land is a fearsome king with a deep, mighty, voice.
- Least that's what I've come to understand.
- And I've also heard it told that he's something to behold.
- Like a lobster, huge and red.
- When he sets out to sleigh with his rain gear on, carting bulging sacks with his big great arms.
- That is so, I've heard it said.
- And on a dark, cold night under full moonlight, he flies into a fog like a vulture in the sky.
- And they call him Sandy Claws.
- There's got to be a logical way to explain this Christmas thing.
[...]