If you’ve watched the KDrama called “My Girlfriend is a Gumiho” where gumiho means nine tailed fox, you would know what this creature is. This creature is exactly like its Japanese and Chinese counterparts, that is when a fox lives for over a thousand years, it would turn into a magical being. It can easily shapeshift and would usually shapeshift into a beautiful woman or man to seduce humans. Though in their human form, there is always a tell tale sign that they could be a gumiho like having fox ears or fox-like face or even the nine tails.
There are a lot of variations to what the gumiho does but most of it centres around how the Gumiho wants to become human. Some tales say they need to abstain from eating or killing anything for 100 days, some say 1000 days and others say they have to eat 1000 men’s livers or hearts over a period of 1000 years just to become human.
So I guess, being a vegetarian for 1000 or even 100 days is almost impossible for the Gumiho because the stories of it eating and/or killing humans are more prominent in legends and in newer literature of it.