Assassin's Teapot, also known as "LiangXin Teapot" in ancient Chinese history, "LiangXin" means two cores in one teapot, which stands for two different beverages in one pot.
Original Story: It is a wine container used by Chinese nobles in ancient times for drinking & merrymaking, they are interested in tricking others with this tool during banquets, maybe that's the reason why someone is a better drinker than you:)
Assassin's Tool: There is also a rumor about this "LiangXin Teapot", it's one of assassin favorite tools to assassinate their target, by using this teapot, they can easily mix regular beverages and poison together, and this caused most the injustices among nobles, trick or treat, that's the killer oath.
Old Man Exterior: People may doubt the figure of this teapot, and who is this old man?
He is one of Eight Immortals of ancient Figures in Chinese Myths, and he represents the God of longevity. People believe that he could bring wellness and wealth.