Gangsta Rayman is a default costume in Rayman Raving Rabbids. He also appears in the GBA version allowing him to stomp on stompable costumes. You can earn this costume after defeating the Intro Boss: Bad Note in the GBA Version of Rayman Raving Rabbids. However he is not in the DS version.
This costume includes darker skin, glasses, a bandana, loose pants, and fingerless gloves, plus a golden dollar sign bling necklace.