In a small bowl mix the taco seasoning with the refried beans.
Spread the bean mixture evenly on an 11 inch plate getting close to the edge.
Carefully spread ¾ cup of the sour cream over the bean mixture.
Add the salsa very gently over the sour cream. If your salsa is really runny, drain off some of the liquid first.
Apply the guacamole mixture over the salsa. I put dollops of guacamole all over and then carefully spread them together so that the salsa doesn't come through.
Around the edge spread the grated cheese.
Top the cheese with sliced olives, diced tomatoes, and sliced green onions.
With the remaining ¼ cup of sour cream, put it into a sandwich bag and clip off the corner. Squeeze the sour cream into a web pattern over the guacamole.
Top with plastic spiders.
Notes
Make it up only an hour or so before you need it if possible. This will give little time for the guacamole to turn brown. If you need to make it up earlier than an hour beforehand, carefully brush a thin layer of lime juice on top of the guacamole with a pastry brush.