In a stand mixer fitted with a paddle attachment, combine the cream cheese, Cheddar, Monterey Jack cheese, butter, salsa and some salt and pepper and beat until smooth. Alternatively, mix all the ingredients in a large bowl with a spoon. Reserve 1/3 cup of the dip and wrap in plastic wrap.
Make 2 balls with the remaining dip, one twice as big as the other, wrap in plastic, and shape into balls. Refrigerate all three portions of the cheese until hardened and cold, 2 to 3 hours.
Unwrap the two balls and coat in the crushed tortilla chips. Place on a platter directly next to each other and make eyes in the smaller ball with 2 olives. To make the legs, arrange 8 green beans to stick out of the "spider's" side, then place a small ball made out of the reserved 1/3 cup dip on the end of each bean and connect another bean to each ball to make long legs.
Serve with vegetables, crackers or tortilla chips.