Starring: Grey Griffin, Richard Steven Horvitz, Vanessa Marshall, Greg Eagles
A Grim Surprise / Beast and Barbarians - S1-E9
Continuity mistake: When Mandy is staring in awe at Billy and Grim's surprise, the flower print on her skirt is missing. (00:13:50)
A Grim Surprise / Beast and Barbarians - S1-E9
Continuity mistake: In "Beast and Barbarians" just before Grim presses the big red button, there is a box of donuts on the table beside him. In the next shot when the control area he is sitting at is blown up, the box has vanished. (00:20:35)
Billy's Mom: Oh sorry, Billy. We weren't laughing AT you, we were laughing with you.
Billy's Dad: I was laughing AT you.
Fiend is Like Friend Without the 'R' - S1-E4
Trivia: Nergal is the villain introduced in this episode. "Nergal" originally was the name of the Babylonian God of Fire and Guardian of the Underworld. In the Bible, he is one of the demons allied with Satan himself. In the series Nergal is associated with the underworld and fire.