Jerk or Treat!

It's Halloween, so I thought I'd see if Spawn had learned any good trick-or-treating jokes at school...

me: Hey, do you know any jokes?
him: [spits]
me: I don't think anyone is going to give you candy for that. Maybe you should just say "trick or treat!"
him: jerk or treat!
me: I'm pretty sure you won't get much candy for saying that either.  Maybe you could learn a joke.
him: or I could do this [spits again, then makes vomiting sound].
me: how about this joke: What's a ghost's favorite fruit?
him: ghost bananas?  ghost marshmallows?
me: those aren't real things.  Marshmallows aren't even a fruit...  A ghost's favorite fruit is boo-berries!  Now you try.  Ask me what a ghost's favorite fruit is...
him: Junk or treat!  Ghosts like blueberries and marshmallows!  Got it!