Combine the cheeses, 1 cup sour cream, and milk in a small cast iron skillet and heat over medium-low heat until the cheeses are fully melted. Stir in the chilis.

Put a little sour cream in a small food storage bag, snip off a small corner, and pipe a spider web over the top of the queso. Make spiders by cutting an olive in half, use one half for the body, and cut the other half into thin strips – spiders have 8 legs so you may need to use another olive. Place the spiders in the web and serve with tortilla chips.