Grampa relieves his Air Force days on The Simpsons. "Let's Go Fly a Coot" is the 20th episode of the shows 26th season.
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Homer finds out that Grampa was once a famous wrestler on The Simpsons. "Gorgeous Grampa" is the 14th episode of the show's 24th season.
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It's that special time of the year on The Simpsons. Look for the family to see its future on the episode "Holidays of Future Passed."
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A picture of Abe Simpson, aka Grandpa Simpson, Homer's rambling, senile father on The Simpsons.
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The Simpsons Quotes

Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side!
Man: (From inside a bathroom stall.) That's a right triangle, you idiot!
Homer: D'oh!

Mr. Burns: Oh, and one more thing: you must find the jade monkey before the next full moon.
Smithers Actually sir, we found the jade monkey. It was in your glove compartment.
Mr. Burns: And the road maps, and ice scraper?
Smithers: They were in there too, sir.
Mr. Burns: Excellent! It's all falling into place...