He must be a South Pole elf.
3 seconds sound clip from the Elf (2003) movie soundboard.
You can hear this line at 01:10:37 in the Blu-ray version of the movie.
Quote context
[...]
- Ooh. Call me elf one more time. Call me elf.
- Miles, I'm sorry. He thinks he's an elf. Listen, Miles. Listen, Miles.
- He must be a South Pole elf.
- You get the hell out of here.
- I don't care that you're an elf, that you're nuts.
- I don't care that you're my son!
[...]