Lan Caihe is the least defined of the Eight Immortals. Lan Caihe's age and sex are unknown. Lan is usually depicted in sexually ambiguous clothing, but is often shown as a young boy or girl carrying a bamboo flower basket.

Stories of Lan's behaviour are often bizarrely eccentric. Some sources dress Lan Caihe in a ragged blue gown, and refer to him as the patron immortal of minstrels. In another tradition, Lan is a female singer whose song lyrics accurately predict future events.

Like all the other immortals he was often said to be in a drunken stupor and he left this world by flying on a heavenly swan or crane into heaven. One day while in a tavern, he had supposedly gotten up to go to the bathroom. But before leaving he flew off on the crane or swan and stripped his clothes on the way up.