It's Charlotte's first day at her new school and she loves everything -- especially her new best friend, Vendetta, a mysterious girl who terrorizes the town with homemade monsters.
Charlotte loves pretending, so Vendetta suggests that she play dead. When Charlotte "haunts her day and night", Vendetta creates a fiend to keep her busy.
After Charlotte beats her score on a "How Evil Are You?" quiz, Vendetta becomes obsessed with uncovering her friend's dark secrets.
Vendetta is horrified when Charlotte updates the school lunch menu. She liked it the old way -- clams, beef jerky and grape punch.
Vendetta gives Mr. Milk a talking toupee that offers to make all of his dreams come true. The fiendish toupee only wants one thing in exchange -- Charlotte's destruction.
To remind everyone how powerful she is, Vendetta erects a giant statue of herself. Charlotte treats it like a big toy, so Vendetta hatches a plan... and some pigeon fiends.
Charlotte's delighted when Vendetta shrinks her -- now she's the same size as her hamster, Buttons! Vendetta's equally thrilled, until she accidentally shrinks herself.
In a fiendish plot, Vendetta replaces Charlotte's mom and dad with lookalikes. Charlotte's parents are hungry for HER, but she's just hungry for a little quality time.
Fed up with Charlotte's happy songs, Vendetta creates a fiend that destroys singers. Now all she has to do is get Charlotte to sing, but that'll be easy right?
Desperate to keep Charlotte away, Vendetta uses her fiend multiplier to make a pack of vicious guard dogs. To her surprise, Charlotte loves the dogs-- and the multiplier.
Charlotte and Vendetta describe their day; Charlotte sings a song about Clamburg; a tempting ad for the onion stand; Vendetta frightens tourists away.
Vendetta decides she's too powerful to sit in school all day. She hires Marvin to run things in her absence, but he may not be up to the task of destroying Charlotte.
Vendetta is angry at her parents for picnicking with Charlotte. She sends Grudge to bring them home, but he comes back with Charlotte's cheerful grandma.
To celebrate the Pancake Festival, Vendetta creates a fiend to flatten Charlotte, but the creature fuses the two girls together instead.
Just as Marion is about to leave Clamburg forever, Vendetta moves in with her. Marion is terrified of Vendetta, but having a powerful friend is kind of nice.
Vendetta makes a tornado fiend to destroy Charlotte's house, but unintentionally attaches it to her own house. Charlotte's antics eventually drive Vendetta insane. Meanwhile, Grudge ventures through harsh environments to get back home.
A commercial for giant pet supplies runs; Charlotte dreams about a world made out of cheese with her "best friend" Vendetta, which destroys later; Charlotte sings a song about living on the moon, while Vendetta sings about its downside.
Charlotte wants Vendetta to make a pony for her, so she makes a giant pony fiend. It rampages through Clamburg and terrorizes the citizens. Vendetta is happy until everyone hides in her house for safety, so she must get rid of "John" the female pony if she wants to get back in her own house.