A leg-spinner is a term referred to a spinner who bowls leg breaks. In other words, a leg spinner's delivery spins towards the off side after pitching (all references made with regards to a right hand batsman).
Apart from the regular leg break delivery a reputed leg spinner possesses a variety of deliveries in his/ her repertoire. They usually posses a googly (one that spins in the opposite direction), a flipper (one that skids and goes straight through) and a faster one (one that is bowled quicker and flatter through the air).
Leg-spin is an art, which requires more of wrist spin unlike off-spin bowling, which has more of finger spin imparted on it. However, there are off-spin bowlers who utilise their wrists to a great extent, example: Muralitharan.
Shane Warne ranks as the top leg-spinner in contemporary cricket with Anil Kumble and Mustaq Ahmed close on his heels. Among yesteryear heroes B S Chandrasekhar of India and Abdul Qadir of Pakistan were regarded as great exponents of leg-spin bowling.