(A live-action and gritty version of Scooby Doo: Zombie Island. It gives a lot of Evil Dead and Blair Witch Project vibes. Also it's genderbent)
The Scooby Doo Gang have lost the intrigue of crime solving and they part ways, only to come back together for Daphne's journalism project. It takes them to Moonscar Island in Louisiana. Late at night, when a person showed up in what looks like a zombie mask, the Scooby gang thinks it's just another person under a mask. Yet, they pull at it and the head falls right off.
It's a real zombie, they're on an island with a horde of zombies growing from the ground and they gotta break the curse before they meet an unfortunate end.