Jack Walker (ジャック・ウォーカーJack Walker) or commonly referred to as Jackie (ジャッキー) is a character that appeared in Pokémon Ranger and the Temple of the Sea. His partner Pokémon may be a Chatot that The Phantom previously owned. According to the Spurt! opening, Jackie is classified as a Rank 9 Ranger.
In Pokémon Ranger and the Temple of the Sea, Jack stole the Manaphy Egg from The Phantom and joined the Lizabeth's family circus to keep it safe. After it hatched and bonded with May, Jack helped Ash and his friends take Manaphy to the Sea Temple to fulfill its destiny to lead the water Pokémon of the temple. He told Ash the reason why he wanted to be a ranger. It was because when Jack was a little boy, he got himself caught in a terrible blizzard until a group of wild Pokémon took him inside a tree and kept him safe and warm.
Before Jack was a Pokémon Ranger, he was a member of the Phantom's crew, and learned of his plan to capture Kyogre. After learning that Manaphy could be used to capture Kyogre, Jack stole the Manaphy egg and fled the ship on a Mantine.