In a bowl, mix together the refried beans, taco seasoning, and taco sauce until well blended and warm.

Smoothly spread the warmed bean mixture evenly in the bottom of a glass pie plate.

Mash the avocado and mix it with lime juice, salt, and garlic powder. Spread this over the layer of beans.

Combine sour cream with enough milk to achieve a thin consistency.

Transfer the thinned sour cream to a squirt bottle and carefully pipe a spider web design over the guacamole.

Sprinkle the black olives, cheddar cheese, chopped tomatoes, and green onion around the edges.

Place a plastic spider in the center for decoration.

Serve with warm tortilla chips on the side for dipping.