hah bumhug
A crazy mix of bah humbug from that old Christmas story; it's what kids yell when they're trying to be cool and act like they're punching each other in the butt.
Hah bumhug! I'm gonna beat you up in the lunchroom!
Hah bumhug! I'm gonna steal your phone!
Hah bumhug! I'm gonna make you eat my sandwich!