The Jade Emperor (玉皇) is the chief of the Daoist gods. His names include Heavenly Grandfather (天公, Tiān Gōng) and the Great Emperor of Jade (玉皇上帝, Yu Huang Shangdi or 玉皇大帝, Yu Huang Dadi).
The Jade Emperor is said to have inherited his post from the first of the Three Pure Ones, the Jade Pure One (Yuqing 玉清), also known as The Celestial Worthy of the Primordial Beginning (Yuanshi Tianzun 元始天尊). In time, the Heaven-honoured One of the Dawn of Jade of the Golden Gate (金闕玉晨天尊) will replace Yuanshi Tianzun.
The Jade Emperor lives in his palace in heaven with his wife the Jade Empress, Tianshang Shengmu (天上聖母, Holy Heavenly Mother), who is often conflated with Mazu (媽祖), and their large family.
Worship of the Jade Emperor:
The Jade Emperor’s Birthday (天公誕) is said to be the ninth day of the first lunar month. On this day Taoist temples hold a Jade Emperor ritual (拜天公, bài Tiān Gōng, literally “heaven worship”) at which priests and laymen prostrate themselves, burn incense and make food offerings.
In the morning of this birthday, Chinese, Taiwanese as well as Hokkien and Peranakan Malaysian Chinese and Singaporean Chinese who practice Buddhism, Taoism and other traditional Chinese religions set up an altar table with 3 layers: one top (containing offertories of six vegetables (六齋), noodles, fruits, cakes, tangyuan, vegetable bowls, and unripe betel, all decorated with paper lanterns) and two lower levels (containing the five sacrifices and wines) to honor the deities below the Jade Emperor. The household then kneels three times and kowtows nine times to pay homage and wish him a long life.
In Penang, Malaysia, a focal point of the Jade Emperor’s Birthday celebrations is Thni Kong Tnua, which gained worldwide fame as one of the featured locations for The Amazing Race 16. The temple, built in 1869, is located at the foot of Penang Hill at the Air Itam suburb near George Town, Penang‘s capital city. Aside from Thni Kong Tnua, the Chew Jetty in the heart of George Town is another focal point of the Jade Emperor’s Birthday celebrations; the festivities in this particular location was captured for a 2014 Malaysian film, The Journey.
~ From Wikipedia
N.B. The most interesting thing I’ve read about the Jade Emperor is that one of his secondary wives is the Horse Head goddess, who cares for silkworms. Unfortunately, I don’t think she actually has the head of a horse, but was merely spirited away after a horse’s skin wrapped itself around her.