White Phosphorus, given the name Willy Peter in Vietnam also used in the book "Fallen Angels"(about the Vietnam war). Usually used as a name rather than an object. Willy Peter was usually used in artillery shells to clear sections of forests rife with Congs. White Phosphorus also eats through skin which made it incredibly painful for the enemy and the shells also acted as fragmentation explosives.
"I'm calling in Willy Peter!"
"Who's Willy Peter?"