Kustopher works with Borgin in 'Borgin's Viands 'n Victuals'. He appears to be in a relationship with his boss. He assures Vicha that he tastes all the meat they sell to make sure it's not from an ever changing list of prohibited meats (mostly sentient creatures). He has an uncanny knack of being able to identify the source of meat by tasting it.
Tall and middle-aged, generally with a serious expression.