What a terribly, terribly lazy joke. The problem is the set-up is incredibly forced. Luann really doesn’t know what “hero” means? She’s 17! What the hell Luann?
Also, there’s some weird stereotyping in this comic. The 3 girls all take the obvious stereotypical choice for their heroes: The nerdy white girl picks Stephen Hawking, the black girl picks Oprah Winfrey, and the blonde girl is too stupid to know what hero means. Take some risks Greg Evans! A white girl can like Oprah too! For added symbolism, you can see a poster for Martin Luther King Jr behind Delta (the black girl) and when she’s talking about Oprah, the entire background turns black. Subtletly does not exist in the world of Luann!
How are the girls even talking anyway? They are clearly eating / drinking in 2 of the three panels! I’ve taken the liberty of altering their text to more accurately portray this conversation:
Much *chomp* better *slurp*
Final verdict: Lazy setup to a bad joke.