The rules, per Cinemonster:

There must be at least 31 films. One film can satisfy multiple criteria.

6 countries
Body Melt (Australia)
Grave Encounters (Canada)
And Soon the Darkness (France)
Infection (Japan)
Devil Doll (UK)
20 Million Miles to Earth (USA)

8 decades
White Zombie (1932) – REWATCH
The Devil Bat (1940)
The Nanny (1965)
The House of Exorcism (1975)
Swamp Thing (1982)
Bride of Reanimator (1990)
Dagon (2001)
Green Room (2015) – REWATCH

2 post apocalyptic or natural disaster related films
Hardware
Soylent Green

1 film with Robert Englund
Zombie Strippers

1 something is underground film
Phantoms

3 Satan/Devil centered films
The House of Exorcism
Rosemary's Baby – REWATCH
Torture Garden

1 Amicus film
Vault of Horror

The worst Dracula film (by Letterboxd rating) that you haven't seen and can access
The Creeps

1 LGBTQ+ connected film
Zombie Strippers

5 Films from De Palma, Wes Craven, Ken Russell, Hitchcock and/or Morehead & Benson
The Last House on the Left (dir. Wes Craven) – REWATCH
The Man Who Knew Too Much (dir. Alfred Hitchcock)
Number Seventeen (dir. Alfred Hitchcock)
Rebecca (dir. Alfred Hitchcock) – REWATCH
Swamp Thing (dir. Wes Craven)

2 Peter Cushing films
The Ghoul
Torture Garden

1 film based on a work of or invoking the name Bram Stoker
Legend of the Mummy

1 film based on a Clive Barker story
Nightbreed – REWATCH

1 film that was released the year that you turned 10
Species – REWATCH

1 Mario Bava film
The House of Exorcism

1 film with an 'x' in the title
The House of Exorcism

1 Tobe Hooper film (There must ALWAYS be a Hooper film)
Body Bags