Prepare the Chicken: If using fresh chicken, cook it in the crock pot on low for 6-7 hours, then shred it with forks.
Mix the Ingredients: In a bowl, combine the shredded chicken, softened cream cheese, ranch dressing, buffalo sauce, garlic powder, onion powder, and half of the shredded cheddar and mozzarella cheese.
Cook: Transfer the mixture to the crock pot and cook on low for 2-3 hours or high for 1 hour, stirring halfway through.
Finish: Once the dip is heated through and bubbly, sprinkle the remaining cheese on top. Cover and cook for another 10 minutes, until the cheese is melted.
Serve: Garnish with green onions if desired. Serve with chips, veggies, or crackers.