The store where Fry buys ham-flavored chewing gum has a sign that says, "Free bag of ice-9 with six-pack". Ice-9 is a fictional form of ice which is solid at room temperature, described by Kurt Vonnegut Jr. in his novel "Cat's Cradle".
Henry Kissinger's Head:
Young man, you have the courage of a hero. And the breath of a fresh summer ham.