Prep the slow cooker: Place chicken breasts in your slow cooker.
Add ingredients: Add softened cream cheese, buffalo sauce, ranch dressing, butter, and ranch dressing packet directly on top of chicken.
Cook: Cover and cook on LOW for 4-5 hours or HIGH for 2-3 hours, until chicken shreds easily with a fork.
Shred and mix: Remove chicken and shred with two forks. Return shredded chicken to slow cooker and stir in cheddar cheese until completely melted and creamy.
Serve: Keep warm in slow cooker on "keep warm" setting. Garnish with chopped green onions and serve with tortilla chips and celery sticks.