After it’s revealed that Billy Loomis (Skeet Ulrich) and Stu Macher (Matthew Lillard) are the Ghostface killers targeting Sidney Prescott (Neve Campbell), chaos ensues. Billy and Stu tell Sidney about their scary-movie-inspired revenge plan to frame her father for the killings, which included carefully wounding each other to look as though they had barely survived an attack from the “real” Ghostface.
However, as tensions run high and their plan begins to fall apart, Stu winds up slumped over the counter, spitting up blood, while Sidney taunts him and Billy on the phone. Billy becomes increasingly manic and whips the phone down, smacking his dying friend in neck in the process. Stu responds with an iconic, expletive-laced wail that was totally unplanned.
In the “Scream” commentary track, Wes Craven said that the phone wasn’t supposed to hit Stu. Skeet Ulrich’s hand was covered in slippery fake blood, so his aim was off, but Matthew Lillard didn’t break character and quickly delivered a funny line. Kevin Williamson added that Stu was an underwritten character, but Lillard’s charisma and wit allowed for plenty of amusing improvised moments.