“[T]he inshore hagfish, found in the Northwest Pacific,[27] is valued as food in Korea. The hagfish is kept alive and irritated by rattling its container with a stick, prompting it to produce slime in large quantities. This slime is used in a similar manner as egg whites in various forms of cookery in the region.”
https://en.wikipedia.org/wiki/Hagfish#As_Human_Food
Please tell me you’re joking.