The firm, which came under fire after a crash on the Smiler rollercoaster at Alton Towers left 16 people injured last summer, has released a trailer for a new Ghost Train at Thorpe Park showing its commitment to rigorous testing.
Merlin has called on illusionist Derren Brown to prank staff at the theme park with the help of a terrifying demon in what the firm have dubbed a highly successful "scare test".
Special effects wizards and prosthetic artists spent three months creating and building the creature which was designed by Derren for the new attraction.
Employees on site at the theme park and the head office were left terrified and kicking themselves for falling for the joke, after the "demon" was let out of its cage and went on the rampage.
The creature is one of the characters to feature within the narrative of Derren Brown’s Ghost Train, which will take punters on a head-spinning train journey with two possible endings.
This isn't the first time this year that slight of hand has been called upon to test a company's latest offering. Last month, mobile firm Samsung enlisted street magician Dynamo to test the camera on its new S7 Smartphone. Dynamo used the device to design the artwork surrounding the product's release.