Grim Adventures - Sperg's Spitballs [HD]
From The Grim Adventures of Billy & Mandy Season 2 Episode 8b: "Substitute Teacher"
[Nergal Jr. gets hit by 2 spitballs]
[Sperg chews and shoots another spitball at Nergal Jr.]
[As Sperg is preparing a fourth, he notices his textbook and gets an idea. He tosses away his straw and chews off half of his textbook. After strenuously chewing, Sperg spits out the giant spitball into his hands and nails Nergal Jr. in the head with it]