The Maze Runner

Gally

An arrogant, dark-haired boy who bullies Thomas on his first day in the Glade. He tells Thomas he has seen him before, during the Changing, and sows suspicion amongst the Gladers. Gally is not particularly popular amongst the Gladers. Following a confrontation with Minho, Gally disappears but reappears to warn the Gladers that the Creators mean to kill them by sending in a Griever to take one of them every night until they are all dead. He is then taken by a Griever himself. Thomas and the other escapees encounter Gally again after escaping the Maze. Gally throws a knife at Thomas, but Chuck steps in the way and is killed. Thomas then attacks and beats Gally mercilessly.

Grievers

Giant slug-like monsters that are armed with mechanical arms and weapons. They do not appear to have faces or heads and it is unclear if they are animals or machines or some sort of hybrid. They roam the Maze at night.