He does it again in Frosty's Winter Wonderland. He first claims to be used to Frosty, but ends up shocked into swallowing his whistle after he finds out that Frosty now has a wife.
Professor Hinkle jumping off the train and falling down the hill. Then a squirrel laughs at him when he gets covered in snow.
For that matter, the sound effects when Hinkle is falling down the hill.
This exchange between Frosty and Hinkle:
Hinkle: Now, give me that hat or else!
Frosty: Or else, what?
Hinkle: Oh! Well, don't bother me with details!
As flawed as Frosty Returns is, it's got Miss Carbuncle, who gives us this absolute gem of a line.
Miss Carbuncle: Before you know it, this darn snow turns into slush. And where's there's slush there's ice, and where's there's ice there's broken hips, and where there's broken hips there's substitute teachers!
And later when the kids are chanting "No more snow" she provides this line
Frosty: "Upset?! 'Upset' is waking up and finding out someone forgot to give you a belly button! 'Upset' is discovering your nose has been stolen to play foos-ball! This ain't upset, kid! THIS IS PANIC!