Doug's Doodle / Doug's Runaway Journal - S1-E10
Revealing mistake: Doug's Doodle: At the end of the episode, when Doug imagines himself as Smash Adams driving out of the classroom, right before he takes off, his car is layered over the desk in front of it. (00:22:36)
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 Takes the Case / Doug's Secret Song - S2-E1
Revealing mistake: The framing of this entire episode is such that the edge of the animation cels is visible. Noted on Paramount+.
Doug's Fat Cat / Doug and Patti P.I. - S3-E1
Revealing mistake: Doug's Fat Cat: When Doug imagines himself reporting Stinky on the phone, when Stinky is chasing Porkchop, her tail is layered over the wall in front of her. (00:02:15)
Doug's Fat Cat / Doug and Patti P.I. - S3-E1
Revealing mistake: Doug's Fat Cat: After Stinky is revealed to be a mother, there is a shot of two of the kittens playing with each other. The two kittens keep turning into the opposite kitten repeatedly (you can tell because they keep flashing opposite colors), indicating that the animation is simply looped over and over. (00:11:14)
Doug and the Yard of Doom / Doug's Garage Band - S3-E12
Revealing mistake: After the "Think Big" number, Doug writes an idea down in his journal. There are a brief couple of shots where the edge of the animation cel is visible. It is a white line that disappears.
Doug's Great Beet War / Doug's Magic Act - S3-E13
Revealing mistake: Doug's Magic Act: When all the items fall out of Doug's mirror cabinet, a purple bottle falls out last, and it is incorrectly layered behind the other items on the floor. (00:17:39)
Doug's Birthday Present / Doug's Fan Club - S4-E5
Revealing mistake: Doug's Fan Club: When Doug and Skeeter walk into the cinema, Doug sees some empty seats, and they start running towards them. In the shot of them running past the movie screen, their heads are transparent. (00:17:38)
Doug's in the Money / Doug's Sister Act - S4-E9
Revealing mistake: Doug's Sister Act: When Doug imagines himself as Smash Adams rising out of the floor in a chair, the animation cel code is visible at the bottom right corner of the screen. (00:17:05)
