In the ultimate rap battle between the protagonist Rabbit and Papa Doc, Rabbit says
1, 2, 3, and to the 4
One Pac, two Pac, three Pac, four
Four Pac, three Pac, two Pac, one
You're Pac, he's Pac, no Pac, none
What on earth is this about? What's more, Rabbit points at members of Papa Doc's entourage while saying this and in fact indicated that "none" is in reference to himself. I've seen claims that it refers to the protagonist considering the members of The Free World as poor imitations of Tupac (which seems a bit of a stretch), and also the claim that it is a criticism of Papa Doc's need to surround himself with lackeys (though Rabbit also has followers with him, so this undermines this theory somewhat).
Four lines near the start of the song give it quite a lot of emphasis, particularly with the counting up, and back down. It also elicits quite a response from the audience, so clearly they consider it to be a significant attack on Papa Doc, but what does it mean? Why does the crowd react the way they do?