1. Wear pajamas to the grocery or just anywhere in public really
  2. Eat their entire meal with their hands
  3. Bathe with siblings that are of a similar age to them
  4. Throw a super crying tantrum in public - like throw themselves on the floor style
  5. Poop in their pants
  6. Pick their nose and eat it
    Suggested by @alanarogerrrrs
  7. Have no teeth at all
    Suggested by @alanarogerrrrs