Spray the inside of your slow cooker with non-stick cooking spray.
Add the softened cream cheese, ranch dressing, and buffalo sauce to the slow cooker and stir until well combined.
Mix in the shredded chicken and 1 cup of the cheddar cheese, stirring everything together.
Cover and cook on low for 2 hours, stirring occasionally.
During the last 15 minutes, sprinkle the remaining cheddar cheese and blue cheese crumbles on top and allow to melt.
Garnish with chopped green onions before serving with tortilla chips, celery sticks, or crackers.