The Grim & Evil Theme Song was the intro, that played before every episode of Grim & Evil. The "song" was basically just Grim and Hector laughing mechanically, followed by an instrumental, which introduced the characters from both shows and an opening quote from Mandy. There is a possible extended version of the theme song, as the end credits consists of Jennifer Hale singing "Grim & Evil" four times, and laughing maniacally as she's done.
Lyrics[]
Intro[]
Grim: Aaaahahahahahahahahaha!
Hector: Mwahahahahahahahahaha!
Grim: Aaaahahahahahahahahaha!
Hector: Mwahahahahahahahahaha!
Grim: Aaaahahahahahahahahaha!
Hector: Mwahahahahahahahahaha!
Mandy: Whatever you do, don't look behind you.
Ending[]
Jennifer Hale: Grim and Evil!
Grim and Evil!
Grim and Evil!
Grim and Evil!
Ahahahahahahahahaha!