The Changelings are a group of animal-men created by Woodgod after he discovered his father's notebooks and learned how to duplicate the very act of creation that made him. Woodgod was no longer alone and they resided somewhere deep in a wooded valley. Woodgod discovers one of his fellow Changelings named Centauron is wounded by an ill General Thunderbolt Ross who was suffering from a nervous collapse at the time. Woodgod discovers Centauron inside a cabin occupied by Rick Jones, Fred Sloan, General Ross and Betty Ross. Doc Samson would soon arrive and Woodgod takes him down. Some of the Changelings appear and they keep the rest of the humans in their custody until Woodgod decides their fate. By their own laws, anyone that would harm a Changeling would die but Woodgod wanted to go over the events before passing judgement on the human captives. Woodgod figured out that Centauron was wounded while searching for another Changeling named Viperus that was freed from the valley. Woodgod felt whoever freed Viperus is partially responsible for Centauron's injury.
A fellow Changeling named Leoninus felt that the humans should die and accused Woodgod of favoring the humans. The Hulk finds the wounded Doc Samson and he tells him that the Changelings have captured his friends. The Hulk leaves Samson and searches for Woodgod and the rest of the Changelings. The Hulk follows the wagon tracks that lead to the Changeling's mountain retreat. Neptunus grabs the Hulk as he passes a bridge and takes him to the water below. The Hulk manages to escape by blowing the water out from the pond and Neptunus is out of commission. The Hulk enters the retreat and is attacked by Minotaurus and Centaurio. During the fight, Siren is holding a healing potion for Centauron. She is distracted by Leoninus who poisons the potion. Siren then gives the potion to Woodgod who is attending to Centauron. Woodgod gives the tampered potion to Centauron and then tries to stop the battle with the Hulk. Betty and Rick plead to the Hulk that his presence there will make things worse and that they would be set free once Centauron recovers. The Hulk shrugs off the Changelings and leaves the village since his friends don't want him there. After the commotion, Betty finds Centauron's lifeless body. Some of the Changelings feel that the humans should suffer for Centauron's death. Leoninus would appear with his own group of Changelings he created and challenge Woodgod's leadership.
The group does not suspect that it was Leoninus who poisoned Centauron and forced the confrontation between the two factions. Leoninus challenges Woodgod's leadership and accuses him of disregarding their laws since his parents were human. Woodgod knew that Leoninus freed Viperus so he could create his evil Changelings. Woodgod attacks Leoninus but is overwhelmed by the evil Changelings. Siren leaves the scene and goes to Woodgod's laboratory. She finds out that it was Leoninus who poisoned the potion with cyanide. Siren then finds the Hulk and Doc Samson engaged in a fight in the forest. She intervenes and tells them that the humans need their help. Back at the village, Woodgod is nearly crushed by an evil Changeling named Elephantine. Siren arrives with help and tells everyone it was Leoninus that poisoned Centauron and is responsible for his death. A huge brawl breaks out between the evil Changelings and Woodgod's original Changelings. The Hulk, Samson and the rest of the humans help Woodgod and the original Changelings win the battle. The humans are free to go but Fred Sloan decides to stay at the village to act as a liaison with Woodgod's group and humanity. Fred is also attracted to Siren and thinks the village will provide him the peace and quiet he needs to complete his biography on the Hulk. Woodgod escorts his new friends out of the village and they promise to keep Woodgod's Changelings and his sanctuary's secret safe with them.