Updated: Apr 14 2021, 6:48 ET RAPPER and hip hop record producer DJ Mustard has accused a social media influencer of stealing $50,000 from his credit card. Mustard claimed he hired Karissa Walker to operate as his personal stylist and shopper, but was left furious after she used his wealth to buy clothes and goods for herself. 3 Who is DJ Mustard? DJ Mustard is a disc jockey, rapper and producer credited with bringing a sound that is a more club-orientated, a form of catchy hip hop to the mainstream charts. A Los Angeles local himself, Mustard is a frequent collaborator with other California-natives, including YG and Ty Dolla Sign.