Willy Pete t-shirt

In the U.S. military — especially in artillery units — “Willy Pete” is the friendly-sounding nickname for white phosphorus, which is basically their way of saying, “Let’s light this place up like a Fourth of July accident.” Artillery crews talk about Willy Pete with the same casual tone other people reserve for discussing lawn fertilizer, even though it’s a substance that burns so hot it could probably cook a steak through a brick wall.

In short: Willy Pete — harmless name, very un-harmless effects, beloved by artillerymen who enjoy saying things that make everyone else nervous.