Continuity mistake: In the principal's office, when everyone's talking about how Chris sent an inappropriate picture, Joe is there. After Joe says "This makes Chris a sex offender", he's got a relatively pointed nose. In the wide shot his nose is rounded.
Revealing mistake: When Peter runs across the dock after getting out of the boat, a large chunk of his body is missing.
There's Something About Paulie - S2-E16
Continuity mistake: When Meg is first seen performing 'Death of a Salesman' she changes position between shots. (00:12:35)
Continuity mistake: When Lois goes to the bedroom, she opens the door and trips the wire across the door. The wire is strung across the bottom of the door but when she turns the light on, it has disappeared.
I Am Peter, Hear Me Roar - S2-E8
Revealing mistake: When Brian says "Well face it Peter, your attitude towards women isn't exactly enlightened", Brian's dog tag is the same color as his fur. It also stays still, even while Brian is moving his head. (00:11:10)
Continuity mistake: As Lois pats Brian, her elbow changes position. (00:16:45)
Chitty Chitty Death Bang - S1-E3
Continuity mistake: After Lois says, "When Meg and Chris turned one I missed everything," it flashes back to Lois writing 'happy birthday Meg' on the cake, and there's wallpaper border at the top of the walls, but when Peter asks her what she's doing in the kitchen the wallpaper border is gone. The paper cups that Lois filled with punch also vanish, and the rolling pin, board, etc. suddenly appear. (00:11:30)
Ready, Willing, and Disabled - S3-E15
Continuity mistake: Right after Lois is telling Peter that he should go to Joe's house, you see a plate and a coffee mug. But right after the angel spirit holds the gun up to Peter's head, and he is walking away from the table, the plate and mug are gone.
Other mistake: When Peter and the gang are watching TV drinking beers, the TV doesn't have any cables on the back. So how has it got power or a TV signal? This mistake was later referenced in "Back to the Pilot." (00:04:16)
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)
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.
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.
Continuity mistake: In the first shot of the pool party, Peter's "President" sash is draped from his left shoulder with the visible letters "n" and "t" in reversed positions. In the following shots the sash is draped correctly from Peter's right shoulder.
Continuity mistake: In the Clam when Brian says about he knows what's going on, Quagmire disappears from behind his drink on the table. (00:10:00)
