I love that too, that's what makes him funny (guess his voice changes because he doesn't want to upset Santa or stress him out, then again, Santa's crabbiness here is funny too).

I know Ha Ha Maybe he's going through puberty a little late. . Wow, that scene just came on while I was typing this. Ha Ha Ha

His voice completely changes when he talks to the chorus of elves.
He's taking the knife out of the Cheese!
Do you think he wants some cheese?

I don't know, but I love this character always getting ticked off at everything. The only time he acts like an ass kisser is when he is talking to Santa. Otherwise he is pretty brash with everyone.