Continuity mistake: In the movie "Channel Chasers," when Timmy and Vicky go into Maho Mushi, Timmy gets a piece of his hat sliced off and Vicky gets the tip of her ponytail sliced off. But in the next shot, they're both back to normal.
Continuity mistake: When Flash plays tag with Faust ("Now you see me, now you don't"), there is a brief shot in which he rushes at Faust - but not inside Hyppolita's palace, but in some high-tech laboratory. Obviously a shot from some earlier series, since the coloring and style are different from the Justice League's.
Night of the Day of the Dead - S1-E24
Continuity mistake: At the Halloween party, after Lizzie notices the bride and groom dolls disappear from the table, the items around the space where they disappeared completely change between shots. (01:20:00)
Continuity mistake: When Emma gets into Jay's car for the first time, she has random braids in her hair. When she gets home and is talking to her parents, she has no braids. When she goes to the ravine, she has braids again.
Fiend is Like Friend Without the 'R' - S1-E4
Continuity mistake: Mandy hits a baseball with one of Grim's bones, yet when we see Grim, there are none of his bones missing from his body.
Continuity mistake: In the episode when Penny went to work with her mom and the Magician comes in with the tiger that is acting strangely. The tiger is sitting on the floor and has just eaten its food. Penny is standing there next to the tiger, the camera goes to her mom for about two seconds, then it goes back on her and the food has returned in the bowl again. Then it's empty again.
Spider's Little Daddy/Tricycle of Terror - S3-E1
Continuity mistake: Mandy's working on her report. The page she's on says "CORN by Mandy." A moment later, she writes the same title on another page.