Character mistake: In "The Drunken Clam", while Quagmire and Joe are playing table tennis, a poster on the wall incorrectly spells "Pawtucket Patriot ale" as "Pawtucket Patrtot ale." (00:00:30)
Continuity mistake: When Peter and the family reach the top of Mt Everest, it shows a long shot of them all by themselves. Cut to Lois talking - another family is suddenly sitting there, and the woman says "we beat you by one hour and 11 minutes." (00:14:00)
Continuity mistake: As Lois pats Brian, her elbow changes position. (00:16:45)
Revealing mistake: When Brian says "Our tickets were in the bags", half of his left hand is missing for a frame.
Revealing mistake: When Brian asks Peter how much money they're getting from welfare, his neck is drawn over his collar, making his head look like it's disconnected from his body.
Continuity mistake: When Chris is saying about the Army being awesome, there is nothing green on his plate. When the shot changes, something green has appeared on his plate. (00:01:20)
Continuity mistake: When Meg gets promoted, there is a gap in the books on the shelf. When she stands up, the gap is gone. (00:18:30)
Continuity mistake: When Lois is carrying Stewie down the stairs, the brick patterns in the wall change between the wide shot and the close-ups. (00:14:10)
Continuity mistake: When Stewie keeps saying "mum", he's not stood next to a rug. When the shot changes, a blue rug has appeared next to Stewie. (00:11:40)
Continuity mistake: When Peter says about suing Dr. Hartman, Lois is holding Stewie who is asleep and facing Peter. When the shot changes, Stewie is now looking towards Brian. (00:08:20)
Continuity mistake: When Peter is playing with Stewie's nose, Stewie's arms are by his side, but when the shot changes, he's got his arms in front of him. (00:08:10)
Continuity mistake: Lois and Brian go outside and celebrate Peter's dad's death, then they come back in and sit down. Behind Lois you see the trash cans when Peter says, "But instead he called me a fat stinking drunk, those were his last words," then it cuts to a closer shot of Peter and Lois, and the trash cans have vanished. (00:12:33 - 00:12:54)
Continuity mistake: When Peter is going for ice cream, his fork simply disappears from his plate. (00:18:40)
Other mistake: One of the ping pong balls that fell off Peter goes through the floor when it hits the ground. (00:00:50)
Revealing mistake: Right after the "Ghost Whisperer" cutaway, while Peter, Chris, and Lois are sitting on the couch, Chris' eyes disappear for a single frame. (00:09:10)
And Then There Were Fewer - S9-E1
Other mistake: When they are chasing Tom around the dining table, they huddle up in a circle. Everyone is looking at Peter talk, and when Doctor Hartman says "Damn, that is awfully risky," if you look at Carl's eyes, they clip outside their eyes to look at Hartman.
Brian Goes Back to College - S4-E15
Continuity mistake: When Brian arrives at Brown, his bag strap is across his body. When the shot changes, it's just on one shoulder. (00:08:00)
Brian Goes Back to College - S4-E15
Continuity mistake: Louis' hand changes places on the newspaper at the start when talking to Brian. Note its position in relation to the column. (00:02:10)
Continuity mistake: While Peter is with Mayor West at Town Hall, when Peter winds up in the trap door, the doorknob on West's office door changes sides (so the door opens the opposite way) and the plant moves away from the corner.