Because some of this has no heterosexual explanation:
In the initial season of the webisodes and up until the movie Fright On, Cleo is painted as the typical mean girl. She uses Ghoulia as a way to get good grades and keep herself on top of the social pyramid. But in the TV special Fright On, she apologizes for her actions and the two ghouls become quite close.
In the unlisted webisode Zom-beach party, the ghouls try to help Ghoulia relax at the beach, with Cleo taking special care to make sure she’s having a good time.
https://www.youtube.com/watch?v=bGlwL9T4-u4
Ghoulia writes about and describes her friendship with Cleo in her diaries:
Cleo likewise writes that she considers Ghoulia her closest confidant and friend:
In the webisode Daydream of the Dead, Ghoulia is despondent due to not being able to attend a comic convention and enter a raffle to win a one-of-a-kinda comic. Cleo rigs this raffle to win the comic for Ghoulia:
https://www.youtube.com/watch?v=GgtGoE74QFs
In the webisode The Need for Speed, Ghoulia obtains a new scooter which is stolen by Toralei. Once she has gotten it back, Cleo especially makes sure that Toralei pays for what she has done to Ghoulia:
https://www.youtube.com/watch?v=eo7csWNWNYs
In the webisode Mauled, Cleo fights Ghoulia’s boyfriend Slo Mo for a spot in line at the mall and when it’s revealed he’s getting a gift for ghoulia she says “BUT I PROMISED-“:
https://www.youtube.com/watch?v=630jn6NB1nA
The diaries included in the SDCC exclusive two-pack with Ghoulia and Cleo reveals that Ghoula was in fact the one to unearth the De Nile tomb. We learn that Cleo was having dreams about Ghoulia before they even met. You can read more about those here
They have another two-pack that is Mad Science themed and you can read those diaries here
The two have equal amounts or more two-packs together than with their respective canon boyfriend.
In the Scare-ific secrets book when asked what she loves about Ghoulia Cleo writes this:
In the Ultimate Sticker Collection, their friendship is described like a fairy tale
In the prelude to Gloom Beach Cleo uses her father’s private jet specifically for Ghoulia because she misses her.
If you have more that you can think of, please include them in the reblogs! I’ll add to this if we get additional content in the future.
You could definitely just read these two as very close friends but they don’t act that way with any of their other close friends.
