Lisa Marie Simpson, voiced by Yeardley Smith, is Homer and Marge's oldest duaghter and the middle child on The Simpsons. Lisa is very intelligent, plays the saxophone, is a vegetarian, Buddhist, and definitely a bit of a young political activist. She's basically the complete opposite of her brother, Bart.
Lisa's Brain: Poor predictable Bart. Always takes 'rock'.
Bart's Brain: Good ol' 'rock'. Nuthin' beats that!
Lisa: Dad, I think he's an ivory dealer! His boots are ivory, his hat is ivory, and I'm pretty sure that check is ivory.
Homer: Lisa, a guy who's got lots of ivory is less likely to hurt Stampy than a guy whose ivory supplies are low.