Quote from : Harry Potter and the Deathly Hallows: Part 1 Movie

Alastor 'Mad-Eye' Moody: [handing out Polyjuice Potion] Fair warning, it tastes like goblin piss.
Fred Weasley: Have lots of experience with that, do you, Mad-Eye?
[Moody glares]
Fred Weasley: Just trying to diffuse the tension.