The explanation refers to a very rich meal. In addition to describing eating, it can also be used to describe a particularly beautiful enjoyment, such as encountering a particularly beautiful scenery, which can be said to be a visual feast.
Taotie is a ferocious beast in ancient Chinese legends, not the nine sons of the dragon. "Zuo Zhuan·Wen Gong's Eighteenth Year": "Shun's minister Yao was a guest of the four gates, and the four evil tribes, Chaos, Qiongqi, Yongzhu, and Taotie, joined the four descendants to ward off Chi Mei. So Yao collapsed and the world As one, we unite to worship Shun as the Son of Heaven, and use his sixteen signs to eliminate the four evils."
Extended information:
Translation: Shun surrendered to Yao, and the princes were in the four gates. Accepting the hospitality, there were four ferocious beasts at that time, Chaos, Qiongqi, Taotie, and Taotie. Yao exiled him to remote areas to resist the harmful monsters in the mountains and forests. Therefore, after the death of Yao, the world was still peaceful and unified. They loved Shun and made him the emperor. Emperor Shun used eight talents from the Gaoyang clan, eight talents from the Gaoxin clan, and a total of 16 people to get rid of the four evil beasts.