Lou the Cop is one of Wiggum's two frequently used police officers.  Lou definitely seems to be the hardest working and most competent of the cops.

Lou Quotes

Bart: Take him away, boys.
Chief Wiggum: Hey, I'm the chief here! Bake him away, toys.
Lou: What'd you say, chief?
Chief Wiggum: Do what the kid said.

Chief Wiggum: Hold it right there, Switches of Eastwick.
Lou: Switches of Eastwick?
Chief Wiggum: I don't want to censor myself. That's how creativity dies.

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!