Episode - 7F22\\
First Aired - 7/11/1991
Mr. Burns is in dire need of a blood transfusion, and Bart is the only one who has the same rare blood type as Mr. Burns, so Homer forces Bart to donate under the impression that the family will get a buttload of cash for the generous deed. But when all they get is a "Thank you" card, Homer writes a strongly-worded letter -- which Bart ends up sending after Marge talks Homer out of putting it in the mail.
!! This episode provides examples of:
* AndroclesLion: Homer tells a variant of the classic story (he throws in Hercules and claims it's from Literature/TheBible) to convince Bart to donate blood.
* DecoyProtagonist: Bart. Homer takes over after Burns' half-hearted thank you to Bart outrages him, and the only significant thing Bart does for the rest of the episode besides follow Homer is make a prank call to Moe's Tavern for "Mike Rotch."
* LostAesop: Discussed in the end, when the Simpsons try to figure out a moral to the story (such as "The squeaky wheel gets the grease") and then realize that something that occurred contradicts the moral. They eventually conclude that "it was just a bunch of stuff that happened."
* StoppedReadingTooSoon: Homer writes an angry letter to Mr. Burns, which starts out as a fake thank you note. Mr. Burns at first reads the thank you part, and is deeply touched, until he later discovers the following sentences.
-->Dear Mr. Burns... I'm so glad you enjoyed my son's blood and your card was just great. In case you can't tell, I'm being sarcastic. You stink! You are a senile, buck-toothed old mummy with bony girl-arms, and you smell like an elephant's butt.
* UngratefulBastard: Homer believes Burns is one for only sending a thank you card after Bart's blood saved his life.
* WhyDontYouJustShootHim: Subverted by Burns.
-->"I could crush him like an ant, but, no. Revenge is a dish best served cold. I'll bide my time until... Oh, what the hell, I'll just crush him like an ant."