Bulb Monsters are a species of robotic creatures created by WICKED, and are fought by the Gladers, Group B, Brenda, and Jorge at the end of The Scorch Trials. The monsters are described as being slightly taller than a normal human, with wrinkled, yellow skin, no faces, bulges where there are supposed to be heads, and four extremely disfigured limbs, chunks for fingers with huge silver blades sticking out of toes, fingers, and shoulders.
A Bulb Monster is defeated by destroying all the light bulbs on its body. Similar to the Grievers, Bulb Monsters are housed or "charged" in spacious white pods big enough to hold four people, as Thomas, Teresa, Brenda, and Jorge manage to squeeze into one. When these pods are activated, the Bulb Monsters fall out, and eventually gain more control of their limbs, thus being described as fast and agile.
The bulb monsters are first seen chronologically by Thomas and Newt in The Fever Code while they are still under development. It was seen in a vat while trying to find Newt's sister Sonya. They killed two girls and one boy in the group of Gladers.