Oswald Priest, better known as Mad Lion, is a dancehall, ragga musician and rapper. He frequently collaborates with fellow hip hop artist KRS-One — most recently on a DVD promoting the Temple of Hiphop. The recipient of the 1994 Source award as Reggae Artist of the Year, he has inspired similar-sounding recordings by such artists as Ini Kamoze, Capleton, and Rayvon.

Priest was born in London. Shortly after moving to Brooklyn, New York, he met reggae performer Super Cat at Super Power Records. At Super Cat's suggestion, he adopted his professional name, an acronym for Musical Assassin Delivering Lyrical Intelligence Over Nations. He blended ragga and hip-hop, and went on to work with KRS-One, with whom he worked throughout the 1990s. His earliest success came in the mid-1980s when he applied his hip hop rhythms to Shabba Ranks' hit single "Jam". His début single "Shoot to Kill" was successful in New York and he reached a wider audience with "Take It Easy", which became the title track of his début album in 1994. He later appeared, along with Queen Latifah, on Salt-N-Pepa's 1997 album Brand New. In 1997 he topped the US reggae chart with "Carpenter".

Launching his own label, Spinners Choice, Mad Lion was working on his debut album when he met and convinced KRS-One to work with him. The collaboration proved fruitful as Lion's single, "Shoot to Kill", sold more than 1,000,000 copies. His next single "Take It Easy", did even better, exceeding the 3,000,000 sale mark.