The Chokuzan were a humanoid species encountered in the Delta Quadrant whose appearance was briefly assumed by Q.
In 2378, while Q Junior was under Captain Kathryn Janeway's care, he stole the Delta Flyer and took Icheb with him as they escaped through a spatial flexure. Once they exited it, far from USS Voyager, they arrived in the Clevari system where they were hailed by a Chokuzan vessel, the crew of which ordered them to surrender their vessel for trespassing. After receiving phaser damage from the Delta Flyer, the Chokuzan commander fired a weapon at the shuttle, which disrupted Icheb's tactical console and injured him with omicron radiation. Junior panicked and returned to Voyager for treatment.
Later, Captain Janeway and Junior returned to the Chokuzan starship, because in order to save Icheb they needed to know what type of weapon was used. When the Chokuzan captain agreed to give them the information to save Icheb, he also told them Captain Janeway would be punished for Junior's actions. Junior did not agree and took full responsibility, even if it meant execution, to save the life of his friend. The commander then revealed himself to be Q, who admitted that he was just testing his son's response. (VOY: "Q2")