Hunter is a young leopard seal who was brought to New York City in the episode Operation: Antarctica when Cecil and Brick accidentally caught her in one of their fishing nets when they were fishing in the waters near Antarctica. After the penguins got Cecil and Brick arrested, again, Private went into a factory nearby to help Hunter to get out of a fish processor, not knowing that she's a leopard seal.
After saving her, Private was fearful at first, but when he finds out that she doesn't eat penguin, he becomes sympathetic when he hears her ask herself which way home was & offered to help her get back to Antarctica. Private brought her to the Penguin HQ, hoping that the others could help her get back home. The penguins helped her reluctantly by launching her to the New York Harbor, so that she could begin her journey home. Private, thinking its not the best for her to go on alone & it was too cruel what the others were doing, went with her when she was launched.
After a roadtrip, Hunter thanked Private for helping her get back to Antarctica. But when Private got captured before he could leave, Hunter came to his defense before he could be eaten, saying to her father that he helped her. Upon learning this, Hunter's father declares Private a hero and holds a celebratory feast with Private as the guest of honor (which is briefly mistaken as having Private as the main course) while forbidding anyone in the herd from eating Private. But for the other penguins who went after them and were captured, she couldn't come to their defense as she said they were against her rescue & Hunter's father interpreted that as them being dinner as he said "Soups on!".
After a talk with Julien, she went back and helped the penguins get out of Antarctica before they could be eaten while they were being marinated in ice cubes. Private saved her father when he was rolling down to some sharp icebergs. Her father thanked him and allowed him to get away. Private said goodbye to her and she launched him to a safe distance with the other penguins and Julien. She thanked her dad for not eating Private & not letting the other seals either.