Continuity mistake: In the flashback when Peter fights Ernie the Giant Chicken, Peter gets knocked off the top of an eighteen wheeler and grabs the second rung at the bottom of the truck's ladder. But when the truck driver sees the pair in his side view mirror, Peter is hanging off the top of the ladder.
Continuity mistake: The position of the hole on the leg of Meg's pants changes. In the scene where Meg is putting the mouse traps around Joe, the hole is on the right side. When they arrive at the house with Randy Newman and Meg is telling Peter that the Twinkee factory in Natick may not even exist, the hole is on the left side. This happens again throughout the episode.