"Knock Knock, Trick or Treat" is a Halloween rhyme and kids' song that captures the spirit of Halloween festivities. In this song, children mimic the act of going door-to-door in costume, knocking on doors, and saying "Trick or Treat!" to receive candy and treats from their neighbors. It's a playful and fun way to engage kids in the Halloween tradition of trick-or-treating while enjoying the spooky and festive atmosphere of the holiday.