Mario & Luigi: Dream Team - Hooskin Trading Quest

During their travels in Wakeport, Mario and Luigi will happen upon a Hooskin who is thinking of proposing to someone close by, but he doesn't have the right item to propose to her. This prompts him to give you an item, which is a plush Zeekeeper, that must be traded for something better with someone else. After receiving the first item, a chain of trades will commence that will have you return to the Hooskin in the beginning, who will give you a reward.