The Grievers are monstrous beasts that live in the Maze, and come out after dark. Their purpose is to kill the Gladers, with the exception of Gally.
They are major villains of the young-adult post-apocalyptic sci-fi Maze Runner book series, and the secondary antagonists of the 2014 movie adaptation, The Maze Runner.
They are described as being bulbous, dark creatures, with many appendages such as spikes, shears, and rods. A Griever can "sting" Gladers, or prick them, which causes extreme pain for up to days or weeks. Stunged Gladers who take the Grief Serum are able to regain some of their memories during "The Changing." If a Glader does not take the serum, they die.
Grievers make whirring and clicking sounds when they move. The machinery inside of them often causes the reflectance of light, as described by Thomas. Grievers have stung four major characters in The Maze Runner: Gally, Alby, Ben, and Thomas.
Grievers appear to be easily tricked, as seen when Thomas and Minho tricked the Grievers into going over the Cliff. It is unknown if the Grievers actually intended to go into the Griever Hole. They are assumed to "charge" in oblong cell-like cages seen in WICKED headquarters, and at the end of The Scorch Trials.
- The name of the creatures, though also shared with that of the legendary Guardian Force known as Griever from Final Fantasy VIII, comes from the word "grievers" (also known as "mourners") that is also originated from the word "grief", which is synonymous with tragedy and loss.