Nelson Muntz.

About Nelson Muntz

Nelson Mandela Muntz is a fictional character, the lead school bully, and a recurring antagonist from the animated television series The Simpsons, where he is best known for his signature mocking laugh "Ha-ha!" He is voiced by Nancy Cartwright. Nelson was first introduced in Season 1's "Bart the General" as an antagonist, but later became more of an anti-hero, continuing to bully those weaker than him while occasionally showing a friendly and sensitive nature underneath. Nelson lives in poverty with his mother in a run-down home, and often shoplifts from convenience stores to get by.