Futurama, Season 2

Prof. Farnsworth:
[spoken] Now let's all of us shut up and sing!

Amy:
[singing] He knows when you are sleeping,

Prof. Farnsworth:
[singing] He knows when you're on the can,

Leela:
[singing] He'll hunt you down and blast your ass from here to Pakistan.

Dr. Zoidberg:
[singing] Oh,

Hermes:
[singing] You'd better not breathe, you'd better not move,

Bender:
[singing] You're better off dead, I'm telling you, dude.

Fry:
[singing] Santa Claus is gunning you down!

[Everyone cheers. Farnsworth takes off his lab coat, exposing himself again.]

Prof. Farnsworth:
Merry Xmas, everyone!