Continuity mistake: At the start of the film the way Meatwad holds onto his guitar changes between shots.
Low Cow
Continuity mistake: When the Teens land in Africa their parachutes land on the ground. We see a shot of Africans and then back to the Teens. The parachutes have disappeared.
Continuity mistake: When Master Shake is performing "Nude Love," Carl's necklace disappears. It reappears, only to disappear again when the Insane-O-Flex explodes.
Continuity mistake: When Frylock is watching New Jersey getting destroyed by the Insane-O-Flex, look for a building to the left through the Ferris Wheel. When Meatwad transforms into a building, the fires briefly stop, then turn on again.