With a bag of styrofoam-balls from the crafting-section at Dollar General we came a long way.
My 6 year old daughter and I painted the styrofoam with acrylic-paint, used some black yarn for the hairs. Wiggly eyes were also from Dollar General.
The spider got painted with black acrylic and the glitter on top of the wet paint. Later, after the paint was dry, I sprayed the glitter-body with Hairspray. Worked excellent.