Cruel, brutal, and thirsting for power, Axe Hand Morgan is the former Marine Commander who was stationed on the Island of Shell Town. He was trusted by the Marines to protect Shell Town, but he took more interest in reigning terror on the town's citizens instead.
The brutal, cruel Marine Captain stationed at the Marine Stronghold at Shell Town, "Axe-Hand" Morgan rules over not just the Marine soldiers under his command with a iron fist, but goes to great lengths to terrorize the citizens of Shell Town in order to get whatever he wants. Along with his spoiled son Helmeppo, Morgan takes advantage of not only of the Marines under his control, but the entire island as well.
Captain Morgan does not evolve as a character in the duration of the One Piece franchise. After his defeat at Shell Town, he is taken in custody by the Marines for his crimes and abuse of power while being the leader at Shell Town. Even then, he is still the same, cruel man he was back when Luffy first encountered him.
At the time Monkey D. Luffy arrives at Shell Town with his friend Coby, the Marines have captured the infamous Pirate Hunter Roronoa Zoro and now hold him captive inside of the stronghold's walls, tied to a post in the courtyard. While young Coby is only interested in becoming a Marine by enlisting at Shell Town, it becomes apparent that Luffy has other ideas. Intrigued by the famous Pirate Hunter, Luffy decides to go and recruit him to join his crew. When Luffy becomes involved with trying to free Zoro by obligating to his request of recovering his three katanas, Captain Morgan steps in and challenges Luffy to a fight. However, Morgan and his men stands no chance against the power of Luffy's Gum-Gum powers or the deadly dance of the blades that Zoro unleashes upon them. While Luffy tries to deal with Helmeppo when the spoiled son of the captain takes his friend Coby hostage, Zoro uses his skill with the blade to crush Morgan in battle, thus ending his reign of terror upon the island of Shell Town. Defeated, Morgan finally falls onto the bad side of his superiors, who begin the steps of removing him from his post as Captain at Shell Town and formally charging him with crimes against the Marines and people he was sworn to protect.
At a later point in the series, Morgan (stripped of his leadership at Shell Town, ranks, and now a criminal in the eyes of the Marines) finds himself being transferred from one Marine warship to another as he continues on his journey to imprisonment. Trying to make a quick escape attempt, he takes his son Helmeppo (now a Marine under the command of Vice Admiral Monkey D. Garp) hostage and gets into a small boat, setting sail into the ocean. Disgusted with his father and wishing to be free from his shadow once and for all, Helmeppo promptly disowns his criminal father and makes his return to the Marine ship, while his disgruntled father slowly drifts away. Morgan has yet to be seen or heard from again in the One Piece franchise.