The funny sequence of what the Prince does to Donald during his lesson; Mickey naming the three secondary trigonometric ratios while using his pea shooter on Donald, before the duck tried to shoot a candle at the Prince, but he accidentally hit Horace's butt instead, causing him to yell out in a high-pitched voice.
Horace: Sire, we have been through this time and time again. It's hypotenuse. Hypote- (gets hit in the butt, high-pitched) -NUUUUUUSE!!
The Prince mocking Donald while mimicking Horace behind his back.
Donald:(points at the Prince) But he started it— Horace: Donald! (he and the Prince point to the door) (Donald leaves in a huff, grumbling)
A Weasel guard's reaction after hearing Pete booting out the actual Prince.
Weasel guard: (spits out beer in shock) You threw out the prince?! (laughs, doing 'shame, shame' hand gesture to him) You're gonna get it! You're gonna get it! NYAH-NYAH-NYAH-NYAH-NYAH, NYA— (Pete suddenly grabs the Weasel by the throat, making him stick his tongue out with a hilarious facial expression.
The Weasel guards screaming as they fell off from midair while attempting to get the Prince, Donald and Goofy who held onto the door.
The Prince cutting Pete's trousers loose, revealing Pete's underpants to all. Heck, seeing the crowd laughing, I've never seen so many tonsils in my life!
Tom admitting he used the Great Seal to crack nuts.