Put the chopped, fresh spinach in a 9x13 casserole dish along with the cream cheese, mayo, sour cream, chopped artichokes, garlic, 2 cups of the mozzarella cheese, parmesan cheese, Worcestershire sauce, Old Bay, kosher salt, and pepper. No need to stir just yet.
Set your smoker or pellet grill to 225 degrees. Place the casserole dish on the grill grate for 2 hours, stirring a few times.
Top with the remaining cup of mozzarella cheese and leave it on the smoker or pellet grill until the cheese melts. Serve with tortilla chips or Fritos Scoops for dipping.