They are large lizard-like creature with a pair of wings, hammer-shaped head and large eyes.
Nothing is known of them, except that one of them was used by the Holy Knight, Vivian, to make Gilthunder follow her orders. The Chimera was secretly following Margret for the past ten years, threatening to kill her if Gilthunder disobeyed her or Hendrickson.
During the infiltration of Liones, Meliodas discovers about Gilthunder's situation. As Margaret ran towards Gilthunder to stop him from killing Meliodas, Meliodas spots the creature and slays it.
The Chimera have the ability to camouflage themselves as well as resistance to lightning-base attacks.