Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: Hook
While Peter, Moira, and Wendy attend the dedication of Wendy's hospital, Hook comes to the real world and abducts the children. This scene itself is fairly unsettling, but it really goes off the charts when the adults return to find the windows smashed, the power cut, and a gash in the wall. Upon going to check on the children, they find the housekeeper Liza, who has an injury on her forehead. When they ask her what happened, her response? "The children were screaming! THE CHILDREN WERE SCREAMING!"
The letter that Hook leaves behind is so nonchalant and so cordial, especially in contrast to the children's fear. It was like a party invitation.
Dear Peter, Your presence is required at the request of your children. Kindest personal regards, JAS Hook Captain
This parallels the original play where the Darlings come back home to find their children's beds empty (they left with Peter Pan). Of course Hook deliberately made their discovery as nightmarish he could by trashing the house, scraping the wall with his hook and knocking out the housekeeper.
Worse, it's hinted that the pirates were watching the children from the moment the family arrived at the house — possibly even longer, since they not only knew that Jack and Maggie were Peter's children, but the exact night that the family would arrive in London.
Maggie: The mean, scary man at the window took [Jack's baseball].
Peter: There's no mean, scary man.
Maggie: But he says he's a window washer!
Before Peter bursts in for the final battle, Hook is about to pierce Jack's ear for his first earring, how? By driving his hook through Jacks earlobe of course!
Gutless's punishment for betting against Hook: he's locked in a small chest (the "Boo Box") where the other pirates drop live scorpions on him. And one pirate mocks his screams with "Boo hoo!"
Captain Hook flat out slew Rufio so nonchalantly as though opening a letter.
The dead crocodile clock (made from the same croc that ate Hook's hand) coming back to life to finish the job by eating Hook alive.
What makes the scene especially weird and creepy is the way it comes completely out of nowhere. Neverland may be a fantasy world, but we don't see anything up until then to suggest that the dead can come back to life. Then Hook tears his hook through the crocodile's belly, and the huge, dry, dusty reptile (who must have been dead and stuffed for decades by that time) opens it's mouth in a roar and starts breaking free of it's support beams...and tilts it's head down to look right at the Captain.