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.
Fiend is Like Friend Without the 'R' - S1-E4
Continuity mistake: When Billy is in the junk yard, his Frisbee is by his feet, but when the ground starts shaking, in one shot it is gone. In the next shot it's back at his feet again. (00:01:40)
