3,000 years ago an ancient land known as Animarium was at war with evil beings known as orgs. Five ancient warriors defended the land from the Orgs while the sixth warrior, Merrick guarded Princess Shayla, whom he had feeling for. The warriors defeated most of the Orgs but they could not defeat Master Org, who had destroyed the Animus Megazord. With little hope left Merrick went on a mission to find an ancient wolf mask that was said to have great powers. Merrick found the wolf mask along with three animal crystals. Merrick used the wolf mask and the animal crystals to summon the Dark Wild Zords, the Wolf, Alligator, and Hammerhead Shark Zords, which combined to form the Predazord. With this Megazord he destroyed Mast Org but his victory came with a price, the wolf mask turned Merrick into the evil Zen-Aku. Zen-Aku began to attack the other warriors so they had no choice but to seal their friend in a hidden tomb. In present day the new Master Org has sought revenge on the successors of the ancient warriors, the Wild Force Power Rangers. The new Master Org freed Zen-Aku in hopes of using him to destroy the rangers. When Zen-Aku awakened he had no memories of being human and a few hazy memories of being imprisoned by the ancient warriors and swore revenge. Zen-Aku's great powers and awesome Dark Wild Zords were far superior to those of the Wild Force Rangers and he defeated them in in every battle he also was able to steal the Elephant, Giraffe, Black Bear, and Polar Bear Zords from them. With every battle the ranger learned more information about this mysterious 6th ranger. Princess Shayla determined that the power of the curse lay within the Dark Wild Zords and to break the spell over Merrick, the Predazord needed to be defeated in battle. To accomplish this, the Rangers were assisted by new Wild Zords, the Rhino and the Armadillo. With these new wild Zords, they formed the Wild Force Megazord Striker mode, which was able to defeat the Predazord, scattering its Animal Crystals. Amidst the chaos lay Merrick, restored back to normal, with a broken wolf mask nearby. The ranger asked Merrick to join their team but he felt guilty for his evil deeds as Zen-Aku and did not feel worthy of such an honor. Merrick later went up against master org and the Quadra Org to get back the power crystals he had stolen as Zen-Aku. Merrick was getting beat badly and was almost defeated, until his old Wild Zords finally answered his calls for help. Merrick was given the Lunar Caller, giving him the ability to morph into the Lunar Wolf Ranger. With these powers Merrick was able to retrieve Elephant, Giraffe, Black Bear, and Polar Bear Zords and give them back to the rangers. The rangers still wanted Merrick to join their team but he was unwilling to get close to them, or to rekindle his romantic feeling for princess Shayla. Merrick could sense when the rangers were in danger and always helped when necessary. As time went by Merrick grew closer to the ranger and eventually excepted them as friends. After Master Org was defeated and the rangers gave up their powers to return to their normal lives Merrick left Turtle Cove to travel the world. He was joined by Zen-Aku, who also sought redemption for his evil deeds.