Doug is Quailman / Doug Out in Left Field - S1-E12
Continuity mistake: The baseball players on Patty's team appear out of nowhere near the beginning. She walks back to the bench in defeat and it's just Doug and Skeeter. A couple of seconds later there are a lot of people in the stands.
Doug is Quailman / Doug Out in Left Field - S1-E12
Continuity mistake: Doug is Quailman: When Doug tells Porkchop to sign his name on the comic book, his pencil is tucked in his ear. When Porkchop prints the page and they both shake hands, the pencil is gone. (00:02:00)
Doug is Quailman / Doug Out in Left Field - S1-E12
Revealing mistake: Doug is Quailman: When Doug, as Quailman, gives everyone's brains back and they start cheering, the computer and boy behind Skeeter are layered over him for one frame. (00:09:24)
Doug is Quailman / Doug Out in Left Field - S1-E12
Other mistake: Doug Out In Left Field: When the kids are carrying Patti at the end, there is a boy behind Doug whose blue shorts keep flashing green, and his light green hair keeps flashing dark green. In the next shot, his hair stays dark green. (00:22:21)