What is the character missing in 「好吃jing」?
I would suggest 「好吃精」 (Mandarin Pinyin: hàochī jīng), where 「精」 is short for something like 「妖精」 (demon). 「好吃精」 then means glutton demon.
See also https://baike.baidu.com/item/好吃鬼, where 「好吃精」 is listed as a synonym.