Su Gu Zhi Huanghelou

In the Northern Song era, when Lu Dongbing was cultivating at the Yellow Crane Tower, he transformed the yellow crane that Fei Yi made from an orange peel, and took it on as a disciple. After Lu Dongbing attained enlightenment and ascended to immortality, the crane stayed behind to watch over the Yellow Crane Tower and continue the Daoist teachings, while awaiting his master's return. (Source: Tencent, translated)