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: Lampshaded and invoked 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 realized that no, something happened that didn't fit, before eventually concluding "It was just a bunch of stuff that happened."
* 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."