Dogs love peanut butter, mine included, but some peanut butters may contain the sugar alcohol Xylitol which could kill your dog. Make sure your pack of sugar-free Trident or Mentos gum is not on the counter either.
Even small amounts of Xylitol can cause hypoglycemia (low blood sugar), seizures, liver failure or even death in dogs.
Here a couple of lists of peanut butters and other foods that contain Xylitol:
https://www.preventivevet.com/xylitol-products-toxic-for-dogs?fbclid=IwAR0HczR1V78nssDOKGTd6-UKjyy8AeSsWLd_mVB-h82O9IB3sibNJL76JZE
https://www.seniordogdays.com/alphabetical-list-of-peanut-butter-for-dogs/?fbclid=IwAR1VvyUPSXPahbgxQOkHVcxINEifxTB6KZXMpYBWBSUcW_hr4lhJ1L6LDSE