The Eld King is first mentioned in the introduction, when the boy in the woods is haunted by memories of him. The Grim Halberdier had planned to return the Eld King to power, and he had nearly succeeded.
Eld Stagger is described in more detail when Kelly Clegg listens to her husband Garrett telling the story of Grunwald's folklore to a group of children. He is said to have been a cruel king who kept the Texas Hill Country in the grip of a curse, preventing humans from migrating into his territory. The only area he did not own was a small part of The Green Ravine River Valley where Momma Kodi resides.
When Brennen came to the Green Ravine, he defeated Stagger's servants and went to challenge the Eld King himself. Garrett describes Stagger as a frighteningly powerful combatant, strong and agile with deadly antlers and the ability to wield the cursed shadow as a weapon. He defeated Brennen, but the wolf had won the respect of Momma Kodi beforehand. The wolf and bear fought him as a team and slew him. The point where he fell, the legend went, became a twisted tree in the forest clearing.
The Grim Halberdier, active once again during the events of Momma Grizzly, has bent every thought and action upon reviving Stagger. This causes the boy great anxiety throughout the book. Being connected to the cursed shadow of the forest, he had been Stagger's slave during the Eld King's reign.
As the sacrifice draws nearer, Stagger's voice begins to speak to Kelly inside her mind, pretending to be her voice of reason and telling her that she has been having psychotic episodes and delusions of grandeur. Kelly is tempted by the comfort of submission, but she ultimately rejects these thoughts.
Upon his defeat, the Grim Halberdier sacrifices himself in place of his intended victim, Laylah Flaherty. The shadow consumes the desiccated man and is only able to revive a rotten, withered version of Stagger.
He immediately takes control of the shadow and uses it to completely surround and darken Grunwald, imprisoning most of the townsfolk in their homes. Kelly challenges him, seemingly alone, but she is joined by Garrett and Gordon, Maggie and Ethan, Firehide, and Kodi. After he has defeated them all and seemingly has Kelly dead to rights, Maggie, Sammie, Rachael, and Kelly's Mother stand in his path.
This action restores Kodi's strength. He defeats her again with the use of the overwhelmingly powerful Leviathan, but Kelly realizes that the key to Kodi's power is Ethan witnessing examples of the maternal protection he craves. Ethan, not the shadow, is the central consciousness of the Leviathan, making him the real King of the Green Ravine.
Ethan finds his confidence, assumes control of the shadow, and turns it on Stagger. Kodi and Firehide arise in shadow forms and work together to pin Stagger to the ground before tearing him in half. When Stagger's body is broken, a small wisp of darkness escapes from his skeleton, representing the release of the Leviathan's grip on his soul.