Volume 2, Episode 14: Cleo and the ghouls are in for an UHHHn-expected surprise when they brave the halls of Monster High for a sleepover on Friday the 13th.
It is Friday the 13th and it makes sure that the Monster High student body knows. Clawdeen and Draculaura make their way through a figurative minefield to the office of Headless Headmistress Bloodgood, where Lagoona, Ghoulia, Frankie, and Cleo already are. The four have just placed their request to spend the night of Friday the 13th at Monster High. Bloodgood urges that they don't, but adds that there are no rules she can use to deny their request. When asked what exactly is so bad about Monster High on the night of Friday the 13th, Bloodgood answers that she doesn't know and doesn't stay to find out either. She jumps on Nightmare's back and flees through the window.
At night, the girls prepare their sleeping bags in one of the classrooms and Cleo thanks her friends for not letting her go through this alone. They discuss the rumors about the night of Friday the 13th at Monster High; that Friday the 13th is the anniversary of something horrible that comes out at night to prowl for victims. Cleo emphasizes it's all just rumors, but then the girls hear footsteps. They step into the hallways to look and discover that the rumors aren't just rumors. Cleo gets the group to split up to get the creature off their trail, saying they'll meet up in the creepateria. Clawdeen and Draculaura form one group and to Clawdeen's annoyance, Draculaura chooses that moment to be reminded that she and Clawd split up too. To calm her down, Clawdeen admits to hiding her brother's letters. Draculaura wants to know why she did that, but the creature approaches and they have to run. They hide in an unlocked classroom, where they find their other friends hiding too. They're not doing a very good job though, as the creature comes after them.
Finally coming face to face with the horror of Friday the 13th, the girls realize the creature is not howling, but crying, and that he wears a party hat. They deduce that rather than the anniversary of something horrible, Friday the 13th is the creature's birthday and that no one ever comes to celebrate it with him. As such, they throw him a party and have a great time until morning, when Toralei, Meowlody, and Purrsephone arrive to, as they believe to be the case, confirm that Cleo and her friends fled Monster High the previous night. They are surprised to find the girls still at school and even more to come face to face with the Friday the 13th monster himself, from whom they flee in terror.
- While the title ostensibly references the superstitious belief that Friday the 13th is an unlucky day, it may also refer to the 1980 slasher film Friday the 13th and its many sequels and remakes since "Frightday the 13th" is also about the anniversary of 'something horrible'.
- The scene with Cleo holding up a bottle of water and noticing the faint tremor of something large approaching due to the water moving is a reference to a famous scene in the 1993 movie Jurassic Park.
- The black cats and giant South American-ish disc previously appeared in the Volume 1 Friday the 13th webisode "Freakout Friday".
- Ghoulia will be once more the one to extinguish Nightmare's leftover flames in "Neferamore".
- Nightmare makes her visual cartoon debut. She was previously heard in "Totally Busted" and "Falling Spirits".
- The two groups agreed to meet in the creepateria, but they meet in a classroom. Or, the accidentally both stumbled into the same classroom despite going two opposite ways.
- Friday the 13th is not an exact calendar date, so one's birthday can't be Friday the 13th.
- When the group leaves the school building the next morning, Cleo's cheek-gem is on her left cheek instead of her right.
- When the werecats flee from the Friday the 13th monster, Meowlody's arm stripes are on the wrong arm.
- This webisode features the second time that Ghoulia says something in Zombie that the other girls respond to in disgust. This was earlier done in "Substitute Creature", including Frankie's exact response of "Oh, that's ghastly!".