Continuity mistake: When the bird with the accordion comes to do his audition at the radio station, the right bellow of his accordion has nothing on it. In the next shot, buttons have appeared.
Continuity mistake: When Porky Pig falls asleep in his boat, he is wearing a red shirt. In his dream, a big fish cuts off the red shirt to cook a now naked Porky. When the dream ends and Porky wakes up back on his boat, his red shirt is still missing, and he's still naked. He should have still had his red shirt on.
Factual error: Two of the little pigs startle the third one who has the gun, and he shoots into the tree, knocking down apples. The weapon appears to be a single-shot blunderbuss with a hammer fire action. He chastises the other two pigs for tricking him and gets up with his weapon to walk away. As he passes them, they blow the horn at him again to scare him a second time, causing him to shoot again. Yet he never reloaded his weapon. The single-shot blunderbuss would not have been able to fire a second time. (00:02:20)
Continuity mistake: When we see "Ben Birdie" on the stage at the start of the cartoon, he is surrounded by a piano, tuba and a drum, but when a mouse appears out of the tuba in the next shot, the drum has completely disappeared.