Charles Montgomery Burns, usually just known as Mr. Burns, is the owner of Springfield Nuclear Power Plant and therefore the boss of Homer.  Mr. Burns is pure evil and most jokes are related to his age and his constant references to the past due to the fact the guy is over 100.

Mr. Burns Quotes

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...

Smithers: People like dogs, Mr. Burns.
Burns: Nonsense, dogs are idiots. Think about it Smithers, if I came into your room and started sniffing at your crotch and slobbering all over your face, what would you say?
Smithers: Umm...if you did it, sir?

The Simpsons Quotes

Anya: (in a girls voice) "Dear Lisa, as write this, I am very sad. Our president has been overthrown...(man's voice) and replaced by the benevolent General Krull! All hail Krull, and his glorious new regime! Sincerely, little girl."
Lisa: (groans)

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!