In an old abandoned theatre, Targoyle and Fargoyle enthusiastically welcome monsters far and wide to the annual Monster Cabaret! Here the monsters are safe to freely express themselves without any humans around.
This year, four human kids have snuck into the cabaret. Westerly, Jade and Sunny all have hopes of revealing monster secrets to the world KC, the oldest of the group, breaks from his tough exterior to reveal that he longs to find his childhood monster friend, Oozy Lumpa.
Unaware of humans lurking around, the Werewolves, led by Tooth and Moonface, perform their signature Rock n’ Roll number showing off their passionate and powerful howls.
The Vampires are next, but this year they’re singing a different tune. Due to humans consuming too many processed foods, they’ve made a significant change to their diet. Vladimer, Vazel, Valexa, Vank and the rest of the Vampires reluctantly profess their new love of vegetables).
Backstage, Sunny, in monster disguise, runs into Oozy Lumpa, a sweet but slimy monster who is longing for her childhood human friend, KC. Sunny runs off, frightened.
During the next cabaret act, the Werewolves enter a friendly competition to see who has the best howl.
Meanwhile, Jade and Westerly continue excitedly filming their documentary in disguise. When KC enters, they realize they’ve lost Sunny! Jade and Westerly split up to go find him while KC thinks again about his long lost monster friend, Oozy.
During the Vampire’s second cabaret number, they tunefully lament on one of the everyday difficulties of being a vampire in a rousing Broadway number.
When Sunny runs into Oozy for the second time backstage, he panics and runs away again. Oozy, left alone, sings about how it feels scaring people away and being alone . This grabs the attention of KC, who finally reunites with his long lost friend! But now the humans have been revealed as spies! The Vampires, whose tempers have already been on the edge due to their new diet, explode into a rock anthem calling all monsters to take a stand against the humans!
In front of the entire Monster Cabaret, the human kids confess that their initial motives for sneaking in were selfish, but have since changed upon learning that the monsters deal with the same issues as humans. As the curtain falls, the cabaret celebrates a monster/human world no longer separated by fear but now joined in understanding and friendship!