Continuity mistake: When Mario, Toad and Luigi are driving to the rebel fort, the seatbelts they are wearing disappear for most of the scene. (00:17:30 - 00:18:40)
Continuity mistake: In season 1 Hobbie was 13 and in season 2 he is 10 years old.
The Leap Home (1) - November 25, 1969 - S3-E1
Factual error: The Post Raisin Bran cereal box sitting on the Beckett family breakfast table in 1969 has a 1990s box design. (00:18:00)
Chûgoku kara kita aitsu! Chotto hen!! - S1-E1
Other mistake: When Ranma is battling Genma at the very beginning, she slides into the main road. Behind her is a vending machine for drinks, only, it's marked "DOLINK" (bad transliteration). (00:03:00)