The Simpsons S02E22 - Blood Feud

The Simpsons is an American animated sitcom created by Matt Groening for the Fox Broadcasting Company. The series is a satirical parody of a middle class American lifestyle
After Mr. Burns falls ill and desperately needs a blood transfusion, Homer discovers Bart has Burns's rare blood type. Homer urges his son to donate some, promising that they will be handsomely rewarded. However having received the blood, all Burns does is send the family a card.